Home

Raven 1.2 User`s Manual - Cornell Lab of Ornithology

1. Figure 5 4 The Configure New Sound Window dialog box The Configure New Sound Window dialog box also allows you to choose a window preset to be applied to the new window when it is first created as discussed in Using sound window presets in Chapter 1 page 41 When you open a single file or a file sequence in a paged sound window a page navigation panel is displayed at the top of the window above any views that are displayed Figure 5 5 Raven 1 2 User s Manual 121 Chapter 5 Advanced Raven Usage Step back Page navigation panel Page start time 122 Paging scrollbar Scroll box Sound 2 010920_000000 aif etc E El Page back LE eish Page forward File sequence number Current file name Figure 5 5 A file sequence of five files opened in a paged sound win dow with page size of 30 seconds The entire file sequence is slightly over 13 minutes long For a single file opened in a paged window the current file name and the file sequence number are not displayed The paging scrollbar The page navigation panel contains a paging scrollbar whose length corre sponds to the entire signal including those portions of the signal that are not presently in memory The scroll box in the paging scrollbar represents the data in the current page i e the data currently in memory The length of this scroll box relative to the length of the entire scrollbar indicates what p
2. 000000 eee eeee 135 Lhe Preset Manager i ivvcisewa asia dt sere as tee aee eee sees 135 The Memory Manager oii6 5050di s sane cie een Oe pete wks Mia wae wee 137 About Raven memory allocation 0 0 0 0 ccc eee 138 The Memory Manager window 0000 cee eee eee 139 Memory usage SUMMALY 0 ae 139 Configuring Maximum Heap Size anann 0c ee 139 The memory usage list 0 00 ce 139 Reclaiming unused M MOry 0 ae 140 Raven program and documentation updates cece secon 140 Chapter6 Preferences Customizing Raven sing uer CRER REENE Eh 143 About this chapter joc 04 pulse Seve ed kat Eden Sate be E EEEE ee 143 About Raven preferences i esi es 6 sa Se os 045 Sees Shee Shy Bae PRE Ss 143 The Raven preference file 00 00200 tees 143 Detault presets ccs ice eccie ieee ei ee Pians lt se Cine nen d eek ewe eet 144 Spectrogram presets ecese ranae aed an baw aetna pi a qb adhane a a ates 145 Recorder presetS 0 000 ccc eee eee 145 Measurement presets 0 0 cee eae 146 Sound window presets 000 00 eee eee ete 146 Color scheme presets 0000 cece eee eee 146 Detault works pace s465 v0s3 ccecea cence d Gere ees heen ses bodes EEES 147 Default directories s oerinoar Aa tae VINA a NARA Ok wa ae ka he 148 Default measurement preciSion 0 cece cece eee eee ee ee ee eeee 148 N AEE edie cused ee ieee Gn ee hh nese a ate Cea tau amen 149 FE
3. Since all three spectrographic views start with calculating spectra of a series of records most of the parameters that must be specified for all three view types are the same The next section briefly explains each parameter Configuring spectrographic views To create a new spectrogram spectrogram slice or selection spectrum view click on the appropriate New View button in the control toolbar Figure 3 3 or choose a view type from the View gt New menu Raven 1 2 User s Manual 75 Chapter 3 Spectrographic Analysis 76 New sap i da selection spectrum E lo lu New waveform New spectrogram slice Figure 3 3 The New View buttons in Raven s control toolbar A dialog box appears containing parameters for configuring the requested type of spectrographic view Figure 3 4 The dialog boxes for configuring spectrogram and spectrogram slice views are identical except for their titles The dialog boxes are identical because both view types cal culate a spectrogram of the entire sound the only difference between spectrogram and spectrogram slice views is in how the data are displayed see How the spectrographic views are related on page 74 The dialog box for configuring a selection spectrum view is the same except that it lacks the Averaging parameter The remainder of this section explains each of the parameters in the con figuration dialog box S Configure New Spectrogram iew 4 x Preset Window Type
4. 0 00 ee ix Boxed NOES errar De eh elke thee beh Lee eh telat Gee eh Pathe RES ix Contextual Menus ssc ex s a sv ed Se ew Os oe ws SS x Keyboard shortcuts and menu mnemonics 00 e eee eee eee ees x Your feedback and updates to this manual 0 cece eee eee xi Chapter1 Getting Started with Raven 004 1 About this Chapler cess sage iets s ives Vee ee eee eee Eee EEN 1 Opening a sound file duis bus ae ae vale E EEA E ae Sieh ares 1 The Raven Window icsick cents eee Eee a ee E COLONIE E IS Ree Cn eR OA 4 The sound window 1 2 6 ee te eee 5 Thetactive VIOW jackain cee ee ta hee Muga a ha Le nya he nd ahaa Mangia 7 Spectrogram brightness and contrast 1 0 sssaaa aaaea 7 Moving and resizing a sound WindoW 00 c eee eee 8 The side panel terased uane ang hated dep alata pula anne ddd thee Madea AEE 8 Playing a sound acr Pina dh r a Yale was Yow openers Ke pehnen ngewe E 8 Playing a selected part of a signal 1 0 00 cece eee 9 Position markers and scrolling playback a sanaaa 0 000 c eee ee 9 Pl yba k ralo Toe rente toe eee Ad eet BE ae ee 10 Changing the position and scale of a view zooming 64 10 Poston OT a VICW yi berre rrokan ate oh oats Geass Pope pte abe teh pela ease aie 10 POSITION MAIKOIs 3 345 fbb teed E ee Ra BR 10 Position vs position location 000 00 ccc tes 13 SCIOND ANS 35 8 ts 8 hee BRR RR yeh E ee O nna ye en ety 13 Scale o
5. BlueWhale aif Nov 7 2002 2 32 PM BowheadWhaleSong aif Aug 23 2002 10 39 AM py Pi Format All Files B Cancel Open Figure 1 1 Raven s Open Sound Files dialog box on a Mac OS com puter Y Open Sound Files xj Lookin CJExampes OOOO OS S E C 2000Hz aif AfricanForestElephants aif Canyonwren wav C BowheadWhaleSong aif C junkwav Sound File Format Type C LarkSpar BeardedSeal aif Bird array 4 channel aif f BlackCappedVireo aif Cy Bluewhale aif File Name cassinsKingbirdwav Noise aif ChestnutSidedvarbler ait Raven aij GO EscreechOwl aif G RBnutha C Humanvoice aif Ei maia Channels Sample Rate Encoding Length Files of Type All Files x Open cancer Figure 1 2 Raven s Open Sound Files dialog box on a Windows com puter The Open Sound Files dialog box displays a scrolling list of the files and directories in the current directory The name of the current directory is given at the top of the dialog box If the current directory is not Exam ples in the Raven program directory find the Examples directory now To move up in the file system hierarchy click on the name of the current directory and select another directory from the pull down menu that appears To move down the hierarchy double click on the name of a 2 Raven 1 2 User s Manual Chapter 1 Getting St
6. a drop down menu from which you can choose a decimation factor and the resulting Output Sample Rate The Output Sample Rate is the sampling rate of the signal that will be acquired A decimation factor of N means that every Nth sample is retained resulting in a sampling rate of 1 N times the input rate Thus a decimation factor of 1 implies no decimation The decimation factor available are 2 4 8 16 and 32 Advanced options scheduled recording 70 If you click on the Advanced button at the bottom of the Configure Recorder dialog an additional tab labelled Schedule becomes available Figure 2 10 The Schedule tab contains parameters that you can set to control when Raven begins acquiring data To hide the Schedule tab click the Simple button that appears in place of the Advanced button Raven 1 2 User s Manual Retroactive Recording Offset Chapter 2 Signal Acquisition Recording Configure New Recorder xj Preset Record To Memory z Input Speed Rate Conversion Display Schedule Retroactive Recording Offset 0 0 seconds Figure 2 10 The Schedule tab of the Configure New Recorder dialog box This tab is visible only after you click the Advanced button which is then replaced by the Simple button The Retroactive Recording Offset field allows you to specify the time off set used in retroactive recording to files When a recorder is already recording to memory retroactive recordin
7. ing spectrum is the same as that of a single filter 174 Raven 1 2 User s Manual Appendix B Spectrum Analysis Third each filter does not completely block the passage of all frequencies outside of its nominal passband For each filter there is an infinite series of diminishing sidelobes in the filter s response to frequencies above and below the passband Figure B 10 These sidelobes arise because of the onset and termination of the portion of the signal that appears in a single record Since a spectrum of a pure tone made by passing the tone through a set of bandpass filters resembles the frequency response of a single filter Figure B 9 a STFT spectrum of any signal even a pure tone contains sidelobes Filter output amplitude dB Frequency Figure B 10 Frequency response of a hypothetical bandpass filter from a set of filters simulated by a short time Fourier transform show ing sidelobes above and below the central lobe or passband The mag nitude of the sidelobes relative to the central lobe can be reduced by use of a window function see text Note that a spectrum produced by passing a pure tone through a set of overlapping filters is shaped like the frequency response of a single one of the filters see Figure B 9 Window functions The magnitude of the sidelobes relative to the magnitude of the central lobe in a spectrogram or spectrum of a pure tone is related to how abruptly the windowed signal s amplitude
8. s column in the selection table The dialog box that appears lets you choose either a decimal or scientific format for mea Raven 1 2 User s Manual Using measurement presets Chapter 4 Selections and Measurements surement values and lets you specify the number of digits of precision used The section Choosing measurements to display in Chapter 1 page 32 describes how to use the Measurement Chooser to choose which measure ments are displayed in the selection table You can use measurement presets to save sets of measurement choices that can later be applied to a selection table without having to add or remove one measurement at a time Mea surement presets also save the format and precision of the measurements that are displayed To save a measurement preset first choose the set of measurements to be displayed in the selection table as described in Choosing measurements to display in Chapter 1 page 32 Then choose Save As from the Preset menu in the Measurement Chooser dialog Figure 4 4 When the Save Measurement List dialog appears enter a name for the preset and click OK 3 Measurement presets must be saved in the folder Presets Measurement List within the Raven program folder You can also create additional folders within the Measurement List folder by clicking on the New Folder icon within the Save Measurement List dialog These folders will appear as submenus in the Preset menu with each sub
9. 34 Delete View View menu 24 deleting a view 24 Delta Frequency measurement 111 device unavailable for signal acquisition 71 device unavailable error for signal acquisition 71 DFT discrete Fourier transform 164 165 DFT Size lock icon 85 DFT size 84 85 166 169 172 173 DFT Size parameter 84 85 Raven 1 2 User s Manual digitizing error 157 Directory parameter recording to file s 58 discrete Fourier transform DFT 74 164 165 Display tab Configure New Recorder dialog box 54 56 dynamic range 157 Edit menu Amplify 129 Copy 34 Copy Image Of 45 Cut 34 Delete 34 Filter gt Around Active Selection 129 Filter gt Around All 129 Filter gt Out Active Selection 129 Filter gt Out All 129 Paste 34 Redo 35 Undo 35 email from within Raven 48 email preferences 151 End Time measurement 32 110 111 EPS graphics file format 45 errors Audio Format Not Supported 71 device unavailable 71 Out of memory 138 Expand Selection Table button 31 exporting images 44 extender point See under selection control points 27 F fast Fourier transform FFT 164 FFT fast Fourier transform 164 file boundary markers in file sequence views 120 File Format tab Configure New Recorder dialog box 56 file formats AIFF 43 56 for recording to file s 56 WAVE 56 File menu Email Feedback 48 Export Image Of 45 New Recorder 46 52 New Sound Window 34 Open Selecti
10. 84 lock icons in Configure New Spectrogram dialog box 84 Lock Overlap in Configure Spectrogram dialog box 84 Low Frequency measurement 32 110 112 M magnitude spectrum 163 164 Max Amplitude measurement 112 Max Frequency measurement 112 Max Power measurement 112 Max Time measurement 112 maximum heap size 138 See also memory allocation Measurement Chooser dialog box 32 33 103 measurement list and window presets 42 measurement presets lt Italic See also lt Default para font gt measurements presets 103 default 146 measurements 31 32 choosing 32 format 102 precision 102 precision default 148 150 presets 103 Memory allocation out of memory errors 138 memory allocation 138 heap size 138 maximum heap size 138 Memory Manager 137 140 Current Heap Size 139 Memory Available 139 memory usage list 139 memory usage summary 139 Memory Used 139 Reclaim button 140 reclaiming unused memory 140 memory usage list 139 memory usage summary 139 Memory Used 139 Raven 1 2 User s Manual menu bar 4 menu mnemonics x Min Amplitude measurement 112 Min Time measurement 113 mm tag in file name templates 59 mnemonics menu x mouse measurement field 6 7 19 Move View Down View menu 24 Move View Up View menu 24 multi channel sounds 120 124 126 editing 125 hiding showing channels 124 selecting channels 125 126 multiple line views 37 38 grouping 38 N n
11. For many types of analysis of these signals sampling rates of 200 to 500 Hz are desirable However the lowest sam pling rate provided by many recording devices is 8000 Hz By choosing a decimation factor of 16 or 32 the signal can be acquired with a sampling rate of 500 or 250 Hz respectively 1 Aliasing is a type of distortion that occurs when sounds that are being digi tized contain energy at frequencies that are more than half the sampling rate Aliasing is explained more fully in Aliasing and the Nyquist frequency in Appendix A page 154 Raven 1 2 User s Manual 69 Chapter 2 Signal Acquisition Recording Decimation Factor If you click on the Advanced button at the bottom of the Configure Recorder dialog an additional tab labelled Rate Conversion is displayed Figure 2 9 You can hide the Rate Conversion tab by clicking the Simple button which replaces the Advanced button Configure New Recorder x Preset Record To Memory eal Input Speed Rate Conversion Display Schedule Input Sample Rate 44100 Hz Decimation Factor 1 MS Output Sample Rate 44100 Hz Figure 2 9 The Rate Conversion tab of the Configure New Recorder dialog box This tab is visible only after you click the Advanced button which is then replaced by the Simple button The Rate Conversion tab displays the Input Sample Rate which is the rate selected on the Input tab see Sample Rate on page 53
12. If the recording level is set too low some features of the signal may not be visible in signal views If the recording level is set too high the acquired waveform will be clipped Clipping occurs when the magnitude of the original analog wave form exceeds the maximum magnitude that can be represented with the given sample size and recording level The result is that waveforms get truncated or clipped in the digital signal Figure 2 7 When viewed in the frequency domain i e in spectrogram or spectrogram slice views clipped signals include spurious harmonics not present in the original analog signal see spectrograms in Figure 2 7 Raven 1 2 User s Manual 65 Chapter 2 Signal Acquisition Recording a 20 0 000 20 90 243 0 244 0 245 0 246 0 247 0 248 g0 243 0 244 0 245 0 246 0 247 0 248 50 243 0 244 0 245 0 246 0 247 0 248 0 000 kiz g0 243 0 244 0 245 0 246 0 247 0 248 Figure 2 7 a Unclipped and b clipped waveform and spectrogram views of a 500 Hz sinusoidal signal The clipped version was acquired with the recording level set too high The unclipped version accurately represents the original signal Note how the tops and bottoms of the waveform are truncated in the clipped version resulting in the appear ance of spurious harmonic energy at 1000 1500 and 2500 Hz in the clipped spectrogram Navigating and Zooming and scrolling selecting data ina When you first create a
13. Raven 1 2 User s Manual 95 Chapter 3 Spectrographic Analysis spectrogram data available at the current time position Figure 3 19 Since Raven by default sets the time position of a view to the start of the sound when a sound file is first opened this message is often shown when a spectrogram slice view is first displayed To see valid data in the slice view simply move the time position marker in any linked waveform or spectrogram view A Sound 8 SpottedHyena aif 1 500 2 000 2 500 gt COL I I Figure 3 19 Three views all linked by time position No data are avail able for display in a spectrogram slice view when the time position is at the very start of the signal before the time of the first spectrum in the underlying spectrogram Significance of the The power values shown at each frequency in a spectrogram slice view spectrum values displayed are expressed in decibels relative to an arbitrary power value of 1 The numeric values for frequency and relative power level at the fre 96 Raven 1 2 User s Manual Chapter 3 Spectrographic Analysis quency where the mouse pointer is located are displayed in decibels dB in the mouse measurement field at the bottom of the signal window Raven 1 2 does not display calibrated sound amplitude mea surements In other words the dB values given by Raven do not represent absolute sound levels Raven s amplitude mea surements can be used to
14. Record to memory button Figure 1 34 A new Recorder window configured for recording one channel to memory Click the triangular green Record to Memory button Figure 1 34 to start a real time scrolling waveform display in the recorder window When you start providing an audio signal by starting playback of a tape or CD or by speaking into a microphone you should see a waveform appear at the right edge of the waveform window and scroll across to the left The Record to Memory button is replaced by a square Stop Recording button and the status field next to the button displays the message Recording to memory When the waveform reaches the left edge the oldest data are discarded to make room for the newest data You can see this happening if you zoom out along the time axis Raven will display a gray background at to the left of the oldest data in the view Time keeps counting up from the right end and scrolling across the view Clicking the Stop Recording button stops recording If you click the button to start recording again Raven clears the Recorder window before beginning to display the new signal By default when recording to memory only Raven records into a 30 sec ond sound buffer You can specify a longer sound buffer when configur ing the recorder see Chapter 2 Signal Acquisition Recording By default Raven initially shows you a waveform view and a spectrogram view in the recorder window Raven can also ca
15. Save As 42 view selection button 7 in multi channel sounds 125 visibility and window presets 42 views deleting 24 display order of 24 hiding 23 multiple lines 37 38 showing 23 Views list Layout tab sdie panel 23 Views pane side panel 23 W wav filename extension 43 WAVE file format 43 56 waveform view 5 window See sound window window components hiding 25 See components window showing 25 window functions 76 79 80 175 176 Bartlett 77 Blackman 77 Hamming 77 Hann 77 Hanning 77 rectangular 77 triangular 77 Window menu Memory Manager 137 window overlap 83 171 172 window overlap in spectrograms 83 window presets 41 42 and recorder windows 55 precedence over other presets 43 window size 42 choosing 171 Window Size parameter 79 80 Window Size slider control 80 Window Type parameter 76 Windows menu 41 workspaces 43 Raven 1 2 User s Manual Index and missing files 44 default 147 opening 44 saving 44 wsp filename extension 44 Y yy tag in file name templates 59 Z zoom buttons 14 Zoom In button 15 Zoom Out button 15 Zoom to All button 16 Zoom to Selection button 16 191
16. Signal 2 default Signal 3 default etc depending on how many signals you ve opened in the cur rent Raven session If more than one signal is open you will see a default linkage group for each signal View Property Time Scale CJ Group 1 Sound 1 Spectrogram 2 Q CJ Sound 1 Default Sound 1 Spectrogram 1 H Sound 1 Waveform 1 CJ New Figure 1 18 The Linkage tab showing the linkage groups for Time Scale corresponding to Figure 1 17 A linkage group is a set of views that are linked to each other by a particu lar property in this case Time Scale Views that are in different linkage groups are unlinked from each other in that property Open the first two folders by double clicking on them or single clicking the icon to the left of each folder icon In the present case the linkage group called Sound 1 Default contains the views called Sound 1 Waveform 1 and Sound 1 Spectrogram 1 Group 1 contains Sound 1 Spectrogram 2 The active view is highlighted and you can activate a different view by clicking on its name To link two views that are presently unlinked drag the icon for one of the views to the linkage group that contains the other In the case shown in Figure 1 18 you can unlink the waveform from Spectrogram 1 and link it to Spectrogram 2 by dragging its icon from the Default folder to the Group 1 folder When you move a view from one linkage group to another t
17. by more than one filter Figure B 9 Consequently when a spectrum or spectrogram is constructed by plotting the output of all of the filters a signal consisting of a pure tone becomes smeared in frequency Figure B 9d Raven 1 2 User s Manual 173 Appendix B Spectrum Analysis Fitter Ao output amplitude fo Input frequency Fiter Ao output amplitude 1 fo f Input frequency Fitter output amplitude ons fo Input frequency d Amplitude fo Frequency Figure B 9 Spectral smearing resulting from overlapping bandpass fil ters a A single hypothetical bandpass filter centered at frequency fp When the input to the filter is a pure tone at frequency fp the output amplitude is Ap For clarity of illustration sidelobes to the main passband are not shown see text and Figure B 10 b Two overlapping filters centered at frequencies fp and f When the filter centered at f is presented with the same input as in a its output amplitude is A4 c A bank of overlapping filters simulated by a STFT Frequency h falls within the passbands of the filter centered at f and of two filters blue and green on either side d Spectrum of a pure tone signal of frequency f produced by the fil terbank shown in c The spectrum consists of one amplitude value from each filter Because the filters overlap the spectrum is smeared showing energy at frequencies adjacent to fo The shape of the result
18. in file name templates 59 New Recorder File menu 52 New Sound Window File menu 34 New Spectrogram Slice button 17 New Waveform button 18 Number of Lines as linkable properties 23 Nyquist frequency 154 156 O opacity 134 Open Selections File menu 110 Open Sound File Sequence dialog box 118 Open Sound File Sequence File menu 118 Open Sound Files dialog box 1 2 115 116 Open Sound Files File menu 1 multiple files 115 oscillogram 5 overlap 169 Overlap parameter 82 83 overwriting files during acquisition 151 P padlock icons in Configure New Spectrogram dia log box 84 Page Back button 123 Page Forward button 123 page increment 120 123 reconfiguring 123 page navigation panel See under paged sound windows page size 120 reconfiguring 123 page See paged sound windows Raven 1 2 User s Manual Index paged sound windows 120 configuring 120 current file indicator 123 current page 120 editing prohibited 120 jump to file 123 jump to time 123 Page Back button 123 Page Forward button 123 page increment 120 123 page navigation panel 122 123 page size 120 123 paging scrollbar 123 selectins in 123 Step Back button 123 Step Forward button 123 step increment 120 123 paging scrollbar See underpaged sound windows Paste Edit menu 34 PCM Pulse Code Modulation 53 Peak Amplitude measurement 113 Peak Time measurement 113 phase 163 ph
19. or lt Option F gt lt W gt Mac OS Raven 1 2 User s Manual About This Manual H New Sound Window Ctrl N New Recorder Ctr R Open Sound Files Ctri 0 ES Open Selection Table Cti Shitt O Open Workspace Close Sound 3 Close All Save Sound 3 4 Save Sound 3 As E Save Selection Table Ctri Shift S E Save Selection Table As Save Active Selection As Save Workspace Save Workspace As amp Print Sound 3 Ctrl P E Page Setup Export Image Of b E Email Feedback Exit Figure 1 The File menu showing keyboard shortcuts and mnemonics Your feedback and updates to this manual If you find errors in this manual or have suggestions for future editions please contact us at raven _support cornell edu From time to time we release revisions of the manual to correct errors and make other improvements To find out whether you have the latest ver sion of the manual and to download any updates use Raven s Check for Updates feature described in Raven program and documentation updates in Chapter 5 page 140 Raven 1 2 User s Manual xi About This Manual xii Raven 1 2 User s Manual Chapter Getting Started with Raven About this chapter This chapter introduces the major features of Raven using some of the sound files supplied with the program as examples Many details of how these features work are deferred until later chapt
20. sound pressures are usu ally expressed in uPa To measure or record sound at a particular location in space we use a device such as a microphone that responds to sound pressure A micro phone produces a time varying electrical voltage that is proportional to the increase or decrease in local pressure that constitutes sound This con tinuous time varying voltage is an electric analog of the acoustic signal The continuous electric signal can be converted to a digital representation suitable for manipulation by a computer as discussed in Appendix A Digital Representation of Sound Time domain and frequency domain representations of sound 162 Any acoustic signal can be graphically or mathematically depicted in either of two forms called the time domain and frequency domain represen tations In the time domain instantaneous pressure is represented as a function of time Figure B 1a shows the time domain representation of the simplest type of acoustic signal a pure tone Such a signal is called a sinu soid because its amplitude is a sine function of time characterized by some frequency which is measured in cycles per second or Hertz Hz The fre quency of a sinusoid is most easily determined by measuring the length of one period which is the reciprocal of the frequency The amplitude of the signal in the time domain is measured in pressure units Once an acoustic signal has been converted by a microphone into an electrical
21. 1 2 User s Manual Chapter3 Spectrographic Analysis About this chapter This chapter is a reference for working with spectrogram spectrogram slice and selection spectrum views in Raven The chapter assumes that you have read Chapter 1 Getting Started with Raven and that you are acquainted with basic concepts involved in short time Fourier transform STFT analysis of time varying signals Terms such as data record equiv alent to frame or aperture filter bandwidth window overlap and window function are explained here only briefly If you are not already familiar with these concepts we recommend that you read Appendix B A Biologist s Introduction to Spectrum Analysis which provides the conceptual background needed to make full use of Raven s spectrogram analysis capabilities About spectrographic views Raven provides three types of views that show the relative intensity of dif ferent frequency components of a sound i e sound spectrum information see Figure 3 1 e Spectrogram views show how the spectrum of a sound varies over time in a three dimensional plot in which time is represented on the horizon tal axis frequency on the vertical axis and the relative power at a given point in time and frequency as a color by default grayscale value e Spectrogram slice views display a single spectrum from the series of spectra that constitute a spectrogram see below plotted as a two dimensional
22. 15 This gap is often narrow enough to be unnoticeable or invisible unless you zoom in to a high magnification Raven 1 2 User s Manual 91 Chapter 3 Spectrographic Analysis Figure 3 15 Time alignment of individual spectra in a spectrogram made with window size 10 samples and time grid resolution 7 sam ples overlap 30 The colored overlays identify the correspondence between spectra and the samples from which they were calculated Each spectrum is associated with the time at the midpoint of the corre sponding source data dashed vertical lines Note the gray area of no data prior to the beginning of the first spectrum Compare with Figure 3 14 Smoothed vs Raven can display spectrograms in either of two modes smoothed the unsmoothed default or unsmoothed Figure 3 16 display 92 Raven 1 2 User s Manual Chapter 3 Spectrographic Analysis Figure 3 16 Close up view of portion of two spectrogram views of a signal digitized at a sample rate of 44 1 kHz The upper view is smoothed the default the lower view is unsmoothed For both views window type Hann window size 512 points overlap 50 To switch between smoothed and unsmoothed displays click the check box next to Smooth Spectrogram in the view s contextual menu or in the View menu when the spectrogram view is active An unsmoothed view more accurately represents the actual data in the spectrogram A smoothed spectrogra
23. 3 5 midway through the second call All three spectra have the same window size 512 points 11 6 mS and fre quency grid spacing 86 1 Hz FFT size 512 samples 3 dB band widths a 141 Hz b 124 Hz c 76 2 Hz The appearance of sidelobes in spectra of finite length signals the use of window functions to reduce their magnitude and differences among the various window functions are discussed further in Appendix B A Biolo gist s Introduction to Spectrum Analysis The Window Size parameter controls the length of each data record that is analyzed to create each of the individual spectra that together constitute the spectrogram You can specify window size either in number of sam ples from the digitized signal or in time units seconds or milliseconds by choosing the preferred unit from the drop down menu The default unit is samples If you specify window size in seconds or milliseconds Raven uses the number of samples that most closely approximates the window size that you enter The maximum value of the Window Size parameter depends on whether the DFT Size parameter is locked as discussed in Frequency grid spacing and DFT size on page 84 When DFT Size is unlocked Window Size can Raven 1 2 User s Manual 79 Chapter 3 Spectrographic Analysis Beta Kaiser window only 3 dB Bandwidth 80 be set to a maximum of 65 536 samples 216 When DFT Size is locked the maximum value of the Window Size
24. DFT Size parameter 84 Frequency Grid Spacing parameter 84 Overlap parameter 83 Preset menu 88 Time parameter 83 Window Size parameter 80 Window Size slider control 80 Window Type parameter 76 Configure New Spectrogram Slice dialog box 17 Configure New Spectrogram View dialog box Window Size parameter 79 Configure Paging dialog box 124 184 Configure Recorder dialog box See Configure New Recorder dialog box Configure Recorder contextual menu 67 Configure Selection Spectrum dialog box 76 Configure Spectrogram dialog box See Configure New Spectrogram dialog box Configure Spectrogram Slice dialog box 76 Configure Spectrum dialog box 76 Configure View Axes dialog box 128 contextual menus x 24 contrast spectrogram 7 88 90 and window presets 42 control toolbar 4 Copy Edit menu 34 Copy Selected Rows selection table contextual menu 108 Ctrl backspace 34 Ctrl G 21 Ctrl L 17 Ctrl N 34 Ctrl O 1 8 Ctrl R 46 Ctrl shift Z 35 Ctrl Z 35 Current Heap Size 139 current page See under paged sound windows Cut Edit menu 34 D date tags in file name templates 59 dd tag in file name templates 59 Deactivate Selection View menu 30 decimation See also sample rate conversion Decimation Factor parameter 70 during signal acquisition 69 usefulness of 69 Decimation Factor 70 default directories 148 default measurement precision 148 150 default presets 144 146 Delete Edit menu
25. Explorer Windows or Finder Mac OS window or from the desktop and dropping the icon anywhere in the Raven window Raver s menu bar appears just below the title bar of the Raven window on Windows computers Figure 1 4 and at the top of the screen on Mac OS computers Figure 1 5 The control toolbar contains controls for common Raven operations When you position the mouse pointer over a control in the toolbar a tooltip appears giving the name of the tool On the left side of the Raven window is the side panel The side panel contains tools that let you control various aspects of how signals are displayed and played back To the right is the Raven desktop which can contain one or more sound windows Raven 1 2 User s Manual Chapter 1 Getting Started New recorder button New view buttons Spectrogram brightness contrast controls Playback controls S 25R rea 1 a Release Candidate 1 0 000 E i He Waveform 1 4 Spectrogram 1 i 4 View selection button 7 att v Axes C Line Titles Position Markers Scrollbars v Selection Control Paints v Selection Labels v Selection Table View Selection Buttons Figure 1 4 The Raven window on a Windows computer with one sound window open The sound window By default when you first open a sound file Raven shows you a sound win dow that contains two views of the sound Figure 1 4 Figure 1 5 The wave form upper view displays an osci
26. Fill Selected Cells gt Up or press Ctrl D Windows or Com mand D Mac OS Using the Annotate Selection command You can enter annotation values into the Annotate Selection dialog box Figure 4 2 for a selection by choosing Annotate Selection from the con textual menu that appears for the selection displayed in any view Depending on whether the selection is active the menu command will either be displayed as Annotate Active Selection or Annotate Selection N Creating selections in multi channel sounds Selections in multi channel sounds can be defined for any subset of the channels in the sound Figure 4 3 By default when you create a new selection in a multi channel sound the selection is defined only in the channel in which you outlined the selection To have new selections defined in more than one channel you must first select the channels in which you want selections to be defined To select channels for creating selections hold down the Ctrl Windows or the Command Mac OS key and either a click in the view selection button at the left edge of any view of each channel to be selected or b click on the entry for each channel to be selected in the channel list in the side panel s Layout tab Channels that are selected are shown with yellow highlighting in their view selection buttons and on their entries in the channel list Raven 1 2 User s Manual 101 Chapter 4 Selections and Measurements Sound 3 Bir
27. For a waveform view the first time in the selection at which a sample with amplitude equal to Max Amplitude occurs For a spectrogram view the first time in the selection at which a spectrogram point with power equal to Max Power occurs Units seconds Min Amplitude waveform The minimum of all of the sample values in the selection Units dimen sionless sample units See also Max Amplitude and Peak Amplitude Raven 1 2 User s Manual Chapter 4 Selections and Measurements Min Time waveform The first time in the selection at which a sample with amplitude equal to Min Amplitude occurs Peak Amplitude waveform The greater of the absolute values of Max Amplitude and Min Amplitude Units dimensionless sample units See also Max Amplitude and Min Ampli tude Peak Time waveform The first time in the selection at which a sample with amplitude equal to Peak Amplitude occurs RMS Amplitude waveform The root mean square amplitude sometimes called effective ampli tude of the selected part of the signal RMS amplitude is equal to where n is the number of samples in the selection and x is the amplitude in dimensionless sample units of the ith sample in the selection Units dimensionless sample units Sle Raven 1 2 User s Manual 113 Chapter 4 Selections and Measurements 114 Raven 1 2 User s Manual Chapter 5 About this chapter Advanced Raven Usage This chapter covers the fol
28. Ham v Size 512 samples vY 3 dB Filter Bandwidth 124 Hz 4 65536 Time Grid gt gt Frequency Grid 7 Overlap 50 percent ja DFT Size 512 v samples S Hop Size 256 samples v S Grid Spacing 86 1 Y Hz Averaging 1 spectra Y _ Auto apply o Apply Reset Close Figure 3 4 The Configure New Spectrogram dialog box Window type Each data record is multiplied by a window function before its spectrum is calculated Window functions are used to reduce the magnitude of spuri ous sidelobe energy that appears at frequencies flanking each analysis frequency in a spectrum These sidelobes appear as a result of analyzing a finite truncated portion of a signal A window function can reduce these sidelobes by tapering the portion of the waveform that appears in each Raven 1 2 User s Manual Chapter 3 Spectrographic Analysis window Window functions are discussed further in Appendix B A Biol ogist s Introduction to Spectrum Analysis Raven provides six different window functions Blackman Hamming Hann sometimes called Hanning Kaiser rectangular and triangular sometimes called Bartlett Each window function is characterized by the magnitude of the sidelobes relative to the center lobe The difference in decibels between the center lobe magnitude and the magnitude of the largest sidelobe is called the sidelobe rejection Figure B 10 on page 175 Ina grayscale spe
29. In a default grayscale spectrogram the floor and ceiling colors are white and black respectively For power values between the floor and ceiling values Raven interpolates between the floor and ceiling colors Changing the brightness of a spectrogram changes the floor and ceiling values by the same amount in the same direction If we plot color value as a function of power changing the brightness has the effect of shifting the brightness vs power function left or right without changing its slope Figure 3 12 Increasing the contrast shifts the floor and ceiling values toward each other which increases the slope of the brightness vs power function without shifting the center point of the function Figure 3 13 Brightness 1 Color g Brightness 2 92 fi f P C4 C5 Power Figure 3 12 Relationship between color and power values in a default grayscale spectrogram for two different brightness settings f and f power floor values for Brightness 1 and 2 respectively c and c gt power ceiling values for Brightness 1 and 2 respectively g and g color val ues associated with power P for Brightness 1 and 2 respectively Increasing the brightness arrow increases the power floor and ceiling values by the same amount The result is that the color associated with a given power P gets lighter Raven 1 2 User s Manual 89 Chapter 3 Spectrographic Analysis Time alignment of spectrogram data 90 Color Contra
30. Reconfiguring an Reconfiguring while acquisition is stopped existing recorder when a recorder is stopped you can reconfigure all of its parameters Choose Configure Recorder from the recorder window s context menu to open the Configure Recorder dialog box You can change any of the parameters in this dialog and click OK When you reconfigure a recorder any data that are already in the recording buffer are lost Reconfiguring while recording While a recorder is running you can change its update rate and display latency see Update Rate on page 54 and Latency on page 55 Other parameters cannot be changed without first stopping the recorder Choose Configure Recorder from the recorder window s context menu to open the Display tab of the Configure Recorder dialog In the dialog there is an asterisk on those tabs that can be modified while the recorder is running Multiple recorder Raven allows you to create multiple recorders with different parameters windows If you need to switch back and forth repeatedly between different sets of parameters e g different sample rates or different destinations for acquired files you can keep multiple recorders open on the Raven desk top and switch among them as needed However only one recorder at a time can be running Advanced options acquiring from recordings at altered input speeds Raven can correct for alterations in the speed at which a recorde
31. The Zoom To Selection button rescales the active view so that the active selection fills the view frame If there is no active selection the Zoom To Selection button is not available In the spectrogram view select a rectan gular area to enlarge by clicking and dragging the mouse pointer Then click on the Zoom To Selection button in the lower right corner of the sound window Figure 1 11 page 15 To reset the horizontal or vertical scale of a view to display the entire axis click on the corresponding Zoom To All button marked with a horizontal or vertical I beam icon Figure 1 11 page 15 Raven 1 2 User s Manual Chapter 1 Getting Started Making a spectrogram slice M A spectrogram slice view is a plot of relative intensity versus frequency at a particular point in time within a signal Figure 1 13 A spectrogram slice represents a vertical cross section through a spectrogram at a single time but rotated 90 so that the frequency axis is horizontal In fact a spectro gram is built of a series of spectrogram slices stacked side by side with their frequency axes running vertically Whereas a spectrogram view shows a series of slices at successive points in time and represents power at each frequency by a color by default grayscale value a spectrogram slice view shows only one slice and represents power at each frequency on a line graph The relationship between spectrogram and spectrogram slice views is explained in
32. a signal or it may consist of some shorter part of a signal Spectral analysis of time varying signals spectrograms and STFT analysis Most signals of biological interest change over time in frequency spectral composition Indeed the changes in spectrum over time are often among the most interesting aspects of such signals But in order to create a spec trum we must examine an interval of time there is no way to measure a signal s instantaneous spectrum An individual magnitude spectrum of a signal provides no information about temporal changes in frequency composition during the interval over which the spectrum is made If we were to make a single magnitude spectrum over the entire duration of a spectrally varying signal such as a typical bird song we would have a rep resentation of the relative intensities of the various frequency components of the signal but we would have no information about how the intensities of different frequencies varied over time during the signal To see how the frequency composition of a signal changes over time we can examine a sound spectrogram The spectrograms produced by Raven 1 Sound spectrograms are sometimes called sonagrams Strictly speaking how ever the term sonagram is a trademark for a sound spectrogram produced by a particular type of spectrum analysis machine called a Sonagraph produced by the Kay Elemetrics Co Raven 1 2 User s Manual 165 Appendix B Spectrum Anal
33. around click and drag on the title bar To minimize it to reduce the whole window to a short title bar at the bottom of the Raven window click on the Minimize icon in the title bar The appearance and location of the Minimize Resize and Close icons depends on the operating system under which Raven is running Figure 1 4 Figure 1 5 Clicking on a minimized window expands it again Click on the Resize icon to maximize the window making it fill the entire Raven desktop When the window is maximized clicking the Resize icon again restores it to its previous size and position Clicking on the Close icon closes the window if you close it you ll have to reopen the sound file again by choosing File gt Open Sound Files or by typing lt Ctrl O gt Win dows or lt Command O gt Mac OS You can also resize the window by clicking and dragging on an edge or corner of the window The left side of the Raven window holds the side panel which contains four tabs Layout Linkage Selection and Playback By default the side panel opens to the Layout tab The side panel is discussed later in this chapter see Unlinking and linking views on page 20 Controlling how views are displayed on page 23 and Multiple line views on page 37 For now notice that Waveform 1 and Spectrogram 1 have appeared in the top half of the Layout tab and Channel 1 in the bottom half The check marks in the corresponding checkboxes tell
34. associated with sound windows and views During the course of normal operations Raven uses memory for many other relatively small internal data objects as well Consequently the Memory Used value is always somewhat greater than the sum of the sizes shown in the list Spectrogram caching may further contribute to a discrepancy between the Memory Used value and the sum of the items in the memory usage list Spectro gram caching occurs when you have requested multiple spectrograms with identical parameters e g for a spectrogram view and a spectrogram slice view or for two spectrogram views that you view at different scales In these cases Raven saves time and memory by computing and storing the spectrogram data only once Even though there is only one copy of the cached spectrogram the Memory Manager will show a duplicate size entry for each view that uses the cached data You can delete a view or close a sound window by selecting its entry in the Memory Manager list then clicking Remove Reclaiming unused memory When you delete a view or close a window the memory that was used for that object eventually becomes available for re use i e it is removed from the Memory Used Category and added to Memory Available This occurs eventually rather than immediately because Raven only reclaims unused memory when it needs to You can force Raven to reclaim unused memory at any time by clicking the Reclaim button in the Memory Manager win dow
35. at 1 in the order determined by the current sort order of the selection table choose Renumber Selections from the selection table s contextual menu Renumbering is useful if the order in which selections were created is not the order in which they occur in the sound or if some selections were cleared creating gaps in the number ing sequence Sort the table by Begin Time then renumber to create an uninterrupted series of selection IDs in time order Working with selections Activating a selection from the selection table Finding the active selection To activate a selection click on any one of its rows in the selection table or choose Activate Selection N from the row s contextual menu If the newly activated selection is not visible in the active view the view s time posi tion is moved so that the selection appears in the center of the view In paged windows see Paged sound windows opening large sounds in Chapter 5 page 120 if the selection is not presently in memory the nec essary of the sound will automatically be loaded and the selection acti vated You can activate successive selections in the table according to the current sort order using either the Activate Next Selection down and Activate Previous Selection up arrow buttons in the table s title bar or the up and down arrow keys If the active selection is not visible in the active view or in the selection table choosing Find A
36. auditory perception is thus based on a frequency domain representation of sounds The complete frequency domain representation of a signal consists of two parts The magnitude spectrum Figure B 2b contains information about the relative magnitude of each frequency component in the entire signal The phase spectrum Figure B 2c contains information about the relative phase or timing relationships among the frequency components Since the phase spectrum is rarely of practical use in most bioacoustic work and is not pro vided by Raven it is not discussed further here Henceforth unless other wise noted we use the term spectrum to refer to the magnitude spectrum alone Raven 1 2 User s Manual 163 Appendix B Spectrum Analysis 164 a Pressure b Magnitude 0 500 1000 Frequency Hz 0 500 1000 Frequency Hz Figure B 2 Time domain and frequency domain representations of an infinitely long sound consisting of two tones with frequencies of 490 Hz and 800 Hz a Time domain b Magnitude spectrum in frequency domain c Phase spectrum in frequency domain The phase of the fre quency component at 500 Hz is arbitrarily taken as a reference and assigned a phase value of 0 The Fourier transform is a mathematical function that converts the time domain form of a signal which is the representation directly produced by most measuring and recording devices to a frequency domain representa
37. be enclosed in double quotation marks Fig ure 5 1 If the names of the files you want to open are listed consecutively with no intervening file names in the file list click on the name of the first file to open then shift click on the name of the last file The names of the two files you clicked and all files between those two will be highlighted and will be shown in the File Name field Each file name in the File Name field will be enclosed in double quotation marks You can type the names of the files that you want to open in the File Names field with each name enclosed in double quotation marks like myFile wav and a space between successive quoted file names After you click OK in the Open Sound Files dialog box the Configure New Sound Window dialog box appears Figure 5 2 In the Multiple Files pane at the bottom of the Window tab click on Open as file sequence in one window After choosing either to open each file in its entirety in a single window or in a paged sound window see Paged sound windows opening large sounds on page 120 click OK A new sound window will appear dis playing all of the audio data from all of the sound files specified in the Open Sound Files dialog box or data from the first page of the file sequence When Raven opens a sequence of files that were individually specified as opposed to given in a list file the order in which data from the different files are displayed is determine
38. c was made with an overlap of 93 8 time grid spac ing 1 45 mS In the low resolution spectrogram a each box is as wide as one data record which in turn is one quarter of the length of the tone The result is a spectrogram that gives an extremely misleading picture of the signal Spectrogram c with a greater record overlap is much smoother than the one with less overlap and it more accurately por trays the continuous frequency modulation of the signal It still provides poor time analysis resolution however because of its large record length notice the fuzzy beginning and end of the spectrogram image of the tone and the poor alignment with the beginning and end of the tone in the waveform Comparison of the spectrograms in Figure B 8 demon strates that improved time grid spacing is not a substitute for finer time analysis resolution which can be obtained only by using a shorter record 1 If the features that you re interested in are distinguishable in the waveform e g the beginning or end of a sound or some other rapid change in ampli tude you ll achieve better precision and accuracy by making time measure ments on the waveform rather than the spectrogram Raven 1 2 User s Manual 171 Appendix B Spectrum Analysis Figure B 8 Different effects on spectrograms of changing record length window size or time analysis resolution and time grid spac ing The signal is a frequency modulate
39. changes at the beginning and end of a record A sinusoidal tone that instantly rises to its full amplitude at the beginning of a record and then instantly falls to zero at the end has higher sidelobes than a tone that rises and falls gradually in amplitude Figure B 11 Raven 1 2 User s Manual 175 Appendix B Spectrum Analysis a Amplitude tip Frequency b A A p x 120 100 Loe oN D j Amplitude dB Figure B 11 Relationship between abruptness of onset and termina tion of signal in one record and spectral sidelobes Each panel shows a signal on the left and its spectrum on the right a A single record of an untapered sinusoidal signal has a spectrum that contains a band of energy around the central frequency flanked by sidelobes as if the signal had been passed through a bank of band pass filters like the one shown in Figure B 10 b A single record of a sinusoidal signal multiplied by a taper or win dow function has smaller sidelobes The magnitude of the sidelobes in a spectrum or spectrogram can be reduced by multiplying the record by a window function that tapers the waveform as shown in Figure B 11 Tapering the waveform in the record is equivalent to changing the shape of the analysis filter in particular lowering it sidelobes Each window function reduces the height of the highest sidelobe to some particular proportion of the height of the cen
40. creating files If a file created by an audio recorder has the same name as an existing file the new file can either overwrite the old one or be placed in a new directory in order to preserve the old file depending on the preference you specify e Return email address to use when sending feedback to the Raven development team Raven preferences are specified in a text file named RavenPrefer ences txt which is placed in the Raven program directory when Raven is installed Each time Raven is launched it loads the preference file To change preference settings you must edit this file If Raven is running when you edit the preference file you will need to quit and restart Raven for your changes to take effect Before editing the preference file it s a good idea to make a backup copy of the file in case you inadvertently damage or delete the file you re editing Raven 1 2 User s Manual 143 Chapter 6 Preferences Default presets To edit the file double click on its icon and the file should open in your computer s default text editing program Alternatively you can open the preference file from within any text editing program that can work with plain text files sometimes called text only or ASCII files file is still named RavenPreferences txt and that it is saved as a plain text file If your word processing program asks you if you want to save the file in the program s own native file format instead
41. data Fig ure 3 14 Figure 3 15 Raven 1 2 User s Manual Chapter 3 Spectrographic Analysis 0 001 Spectrum 1 Figure 3 14 Time alignment of individual spectra in a spectrogram made with window size 10 samples and time grid resolution 10 samples overlap 0 The waveform and spectrogram are linked in time position and scale and have been zoomed in to show individual samples The colored overlays identify the correspondence between spectra and the samples from which they were calculated Each spec trum is associated with the time at the midpoint of its corresponding data interval dashed vertical lines Compare with Figure 3 15 If the window overlap is set to 0 the left and right edges of each spec trum are aligned with the start and end of the source data Figure 3 14 However if the window overlap is greater than 0 the edges of individ ual spectra can t be aligned with the edges of the sample window because the width of the displayed spectrum i e the time grid resolution or hop size is smaller than the width of the source data Figure 3 15 Whenever a spectrogram s time grid resolution is less than the size of the spectrum window i e whenever window overlap is greater than 0 there is a gap between the time of the first sample in the signal and the left edge of the first spectrum in a spectrogram where Raven displays the no data color gray by default Figure 3
42. down the lt Ctrl gt Windows or lt Command gt Mac OS key while clicking on additional rows after selecting the first row Rows that are selected are highlighted in color To copy the selected rows choose Copy Selected Rows from the selection table s contextual menu or press lt Ctrl Shift C gt Windows or lt Com mand Shift C gt Mac OS To clear a selection means to remove the selection information without modifying the audio data contained in the selection In contrast to delete a selection means to delete the audio data contained in the selection as well as the selection information Deletion and other editing operations on selections are discussed in Cut Copy Paste and Delete in Chapter 1 page 34 To clear the active selection do one of the following e Choose View gt Clear Active Selection e In any view Choose Clear Active Selection from the selection s context menu e In the selection table Choose Clear Selection N from the context menu for any of the selection s rows To clear a single inactive selection do one of the following e In any view Choose Clear Selection N from the selection s context menu e In the selection table Choose Clear Selection N from the context menu for any of the selection s rows To clear multiple selections at once highlight rows from those selections in the selection table then choose Clear Selections from the context menu for any of the highlighted
43. ee ee eee eee 108 Copying pasting and cloning selection boundaries 108 Creating duplicate selections at different times 109 Cloning selections 2 2 0 te teenies 109 Using cloning to segment a SOUNd 1 0 ee 109 Selection labels 2 44 Vea vids ei Aaa We Lae VAN AS ee Rs 109 Saving and retrieving selections cc cece cece cee eee eens 110 Format of selection files 2 0 0 0 cee eae 111 Measurements sose renoier eona cee cece eee eee eee ee eee essences 111 Advanced Raven Usage vkiacietcegeeueues 115 About this chapter sissors teas ee he Mee EN es ei tae eS hte 115 Opening multiple sound files in separate windows 6 115 Opening file sequences 0 24 ccc ehiy tania theese Chasewec ce hene sae awaes 117 Using a list iloi nierien Beh eile tt Dea ee etd leans ee Oe as een 117 FormatOf a Hst rosses Ge delete SEa Ma atin ee Ege ginle Lae ares 118 Selecting files in a sequence individually 0 0 0 0 eee eee 119 Paged sound windows opening large sounds 0ee 0000 120 Configuring a new paged sound window 00 0c eee eee 120 Navigating through signals in paged sound windows 200 121 The paging Scrolla E raa mea rA E E EE eee 122 Moving the page incrementally the Page and Step buttons 123 Jumping directly to a particular time within a signal 04 123 The current file indicator jumping to a par
44. example a 16 bit sample value of 16 384 half of the full scale value of 32 767 if saved in a 24 bit signal would be rescaled to a sample value of 4 194 304 half of the full scale value of 8 388 607 27 2 The actual total size of AIFF or WAVE files is slightly larger than the number of bytes of audio data they contain because files in either format include a header that contains information such as the sampling rate and the number of bytes of data in the file Raven 1 2 User s Manual 57 Chapter 2 Signal Acquisition Recording 58 S Configure New Recorder xj Preset Record To File z nat File Name Directory Browse Sound File Example Start Time Now Other so dd hh mm Figure 2 4 The File Name tab of the Configure New Recorder dialog box Directory You can specify where to save acquired files either by typing a pathname Sound File s e g c SoundData wrenProject 05May2002 or by browsing through your computer s file system Click the Browse button to obtain a browser dialog that lets you choose a directory folder in which to save acquired files You specify the name of the file s in the Sound File s field For single file acquisition the file name can be a simple text string that you type directly into the Sound File field or it can be a file name template that incorporates date and time information that Raven fills in at the ti
45. frames 22 050 sample frames per second If only a single channel is acquired the file would contain 100 000 samples a stereo signal would contain twice that many If the files are saved with a sample size of 16 bits 2 bytes a single channel file would contain 200 000 bytes of data a stereo file would con tain 400 000 bytes If you choose Record to File or Record to File Sequence the File Name or File Names tab appears note the plural tab label when recording to file sequences The fields on these two tabs allow you to specify where to save acquired files and how to name them The only difference between the File Name and File Names tabs is that the latter allows you to specify a name for a list file which is required when recording to file sequences See Recording to a file sequence on page 61 for more about list files This section explains how to specify file names for both single file and file sequence recording 1 In general individual samples in a signal of sample size n can have 2 possible values from 2 to 2 1 1 Thus Raven s 16 bit internal representation has 65 536 2 possible sample values from 32 768 to 32 767 If you save a file with a sample size other than 16 bits individual sample values are rescaled so that their values relative to the new range of possible values given the new sample size are the same as their 16 bit values relative to the range of possible 16 bit val ues For
46. graphical controls Swatches HSB RGB o Figure 5 14 The HSB hue saturation brightness color chooser in the Color Scheme Editor dialog Hue Values for hue H must be between 0 and 359 The current hue is indicated by the position of the slider control to the left of the vertical color bar To change the hue move the slider up or down or type a new value in the H field and press lt Enter gt Saturation and Brightness Values for saturation S and brightness B must be between 0 and 100 The large square panel to the left of the hue slider represents possible combinations of saturation and brightness The horizontal axis of the square represents color saturation ranging from 100 at the left edge to 0 at the right edge The vertical axis of the square repre sents brightness ranging from 100 at the top edge to 0 at the bottom edge To set the saturation and brightness of the selected color scheme element click on the point within the square that corresponds to the desired satura tion and brightness You can also drag the small white circle that indicates the current saturation and brightness within the saturation brightness square or type new values in the S and B fields and press lt Enter gt for each one RGB color chooser The RGB color chooser Figure 5 15 allows you to choose colors for each element in a color scheme by specifying the relative amount of red green and blue that are added together to
47. grayscale value in each box represents an estimate of the relative power in the corresponding frequency band and time inter val Filter bandwidth 124 Hz window size record length 512 sam ples 11 6 mS Grid spacing 5 8 mS x 86 1 Hz Raven lets you specify the spacing between gridpoints in the time dimen sion and thus the width of the boxes in an unsmoothed spectrogram In Raven s Configure Spectrogram dialog you can specify the time grid spacing also called hop size directly or indirectly by specifying the amount of overlap between successive records You specify the record length of a spectrogram in Raven by entering the size of a window function Window functions are discussed in Window functions on page 175 The spacing between gridpoints in the frequency dimension is determined by the DFT size Raven chooses DFT size automatically using the smallest power of 2 which is greater than or equal to the window size in samples The relationships between time grid spacing and record overlap and between frequency grid spacing and DFT size are discussed below See Chapter 3 Spectrographic Analysis for a detailed discussion of how to control these parameters in Raven Grid spacing should not be confused with analysis resolution Analysis res olution for time and frequency are determined by the record length and bandwidth of a STFT respectively Analysis resolution describes the amount of smearing or blurring of tem
48. in choice of sampling rate The default audio input device on most computers provides for one or two channel stereo acquisition For signals that are acquired in stereo the Left and Right channels are identified within Raven as Channel 1 and 2 respectively To acquire only one channel uncheck either the Left or Right checkbox The remaining channel will be acquired as Channel 1 If you selected a device that supports input of more than two channels each channel is represented by a numbered checkbox If you disable input of some channels data from the channels that are recorded will be repre sented in the resulting acquired signal in channel number order and renumbered sequentially beginning at Channel 1 For eample if you are recording from a 16 channel input device and you select only input chan nels 1 5 7 and 12 then data from these channels will be represented in channels 1 2 3 and 4 respectively of the acquired signal The Sample Format drop down list shows all of the sample formats avail able for the selected virtual recording device The default input device on most computers supports two formats 8 bit and 16 bit signed PCM Pulse Code Modulation A larger sample size more bits results in a better quality digitized signal higher signal to noise ratio but may also increase the storage requirements for signals saved to disk files See Appendix A Digital Representation of Sound for a discussion of the trade off
49. is equal to the DFT Size Window Size slider control Beneath the Window Size field is a slider control that provides an alternate means for changing the window size Sliding the control to the right increases the window size The control is logarithmic the farther the slider is moved to the right the more the window size changes in response to a given movement The window size slider is useful primarily when the Auto apply checkbox is checked see Apply and Auto apply on page 87 When Auto apply is turned on Raven recalculates the spectrogram imme diately as you adjust the slider allowing you to instantly see how changes in window size affect the tradeoff between time and frequency resolution Use of the Window Size slider with Auto apply turned on may result in unacceptable delays in redrawing the spectrogram with longer signals and or slower computers For the Kaiser window you can set an additional parameter called Beta to values between 0 and 20 For a given window size higher values of Beta result in larger filter bandwidths and smaller sidelobes 3 dB bandwidth is the filter bandwidth of the individual analysis filters in the filterbank simulated by the short time Fourier transform STFT with the selected window type and size see Appendix B A Biologist s Intro duction to Spectrum Analysis Specifically the 3 dB Bandwidth field dis plays the width in Hz of the main lobe of the spectrum of a sinu
50. line graph with frequency on the horizontal axis and rela tive power in decibels on the vertical axis e Selection spectrum views show the average spectrum of a sound over the time interval defined by the active selection Raven 1 2 User s Manual 73 Chapter 3 74 Spectrographic Analysis rogram 1 pe kHz0 000 2 4 6 8 10 Figure 3 1 Raven s three spectrographic views The spectrogram slice shows a single spectrum from the spectrogram at the time indicated by the time position marker 19 67 seconds The selection spectrum shows the average spectrum over the time interval defined by the high lighted selection in the spectrogram How the To calculate any one of the three spectrographic view types Raven divides spectrographic a sound or a selected portion of a sound into a series of successive short views are related time segments or records and calculates a single spectrum for each record using an algorithm called the discrete Fourier transform DFT For spectro gram and spectrogram slice views this process is performed for the entire sound For selection spectrum views only the part of the sound within the time interval of the active selection is processed In a spectrogram Raven displays the spectra of all of the records arranged successively from left to right according to the time of the corresponding record in the sound Each spectrum is displayed as a tall narrow bar Fig ure 3 2 upper v
51. low resolution time grid and unsmoothed spectrogram calculated on a higher resolution time grid The signal is part of a song from a Cassin s kingbird digitized at 44 1 kHz All three spectrograms use a 300 sam ple Hann window a Unsmoothed spectrogram on default time grid Time grid spacing 3 4 mS 150 samples 50 window overlap b Same spectrogram parameters as a but with smoothed display c Unsmoothed spectrogram with higher resolution time grid Time grid spacing 68 mS 30 samples 90 window overlap The rapid peri odic frequency modulation is more clearly represented in c than in a or b Spectrogram slice views Time position of a A spectrogram slice view like a spectrogram view has a time axis and a spectrogram slice time position Unlike a spectrogram or waveform view however the time view axis of a spectrogram slice view is not displayed In order to change the time position of a spectrogram slice view its time position must be linked to a waveform or spectrogram view see Unlinking and linking views in Chapter 1 page 20 You can then change the time position of the spectro gram slice view by moving the time position marker of the linked wave form or spectrogram view If the spectrogram slice view s time position is before the spectrum time of its first spectrum see Time alignment of spectrogram data on page 90 Raven displays a message in the view pane indicating that there are no
52. measurement field at the bottom of the Raven window displays the frequency at the mouse pointer location and the relative intensity at that frequency for the time slice shown When you request a spectrogram slice view Raven actually calculates an entire spectrogram of the signal but only displays one slice at a time A spectrogram slice view thus has a hidden time axis Which slice of the underlying spectrogram is displayed is determined by the view s time position By default the time position of a spectrogram slice view is linked to the time positions of waveform and spectrogram views As you move the time position marker of a spectrogram view any spectrogram slice Raven 1 2 User s Manual 19 Chapter 1 Getting Started view that is linked to it is continually updated to show the cross section of the spectrogram at the time position marker Even though a spectrogram slice view has a time position it does not have a time scale since the time axis of the underly ing spectrogram is not displayed By default new spectrogram and spectrogram slice views are also linked to each other by frequency position and frequency scale When you move the frequency position of a spectrogram the frequency position of any linked spectrogram slice views move as well and vice versa Similarly when you zoom the frequency scale of any spectrogram slice view the fre quency scale of any linked spectrogram zooms as well Remember th
53. obtain accurate relative measure ments within signals Selection spectrum views Significance of the spectrum values Raven updates selection spectrum views whenever the active selection changes If there is no active selection or if the active selection is shorter than the window size specified in the current view parameters selection spectrum views display a text message indicating why no spectrum is shown By default selection spectra are shown in red to distinguish them from spectrogram slice views shown in blue by default You can specify a dif ferent color for selection spectrum views by editing the color scheme as discussed in Editing color schemes in Chapter 5 page 129 The power values shown at each frequency in a selection spectrum view displayed are expressed in decibels relative to an arbitrary power value of 1 The numeric values for frequency and relative power level at the fre quency where the mouse pointer is located are displayed in decibels dB in the mouse measurement field at the bottom of the signal window Changing parameters for an existing spectrographic view To change any of the parameters of a spectrogram spectrogram slice or selection spectrum view choose Configure View from the view s contex tual menu or from the View menu when the view is active You can then enter new parameters into the dialog box that appears then click Apply or OK Raven 1 2 User s Manual 97 Cha
54. parameters using com mands on the Preset menu within the Configure Spectrogram dialog A set of saved spectrogram parameters is called a spectrogram preset To save a preset choose Presets gt Save As When the Save Spectrogram Param eters dialog appears enter a name for the preset and click OK Spectrogram Parameters within the Raven program folder You can also create additional folders within the Spec trogram Parameters folder by clicking on the New Folder icon within the Save dialog These folders will appear as sub menus in the Preset menu with each submenu listing the presets in the corresponding folder b Spectrogram presets must be saved in the folder Presets To retrieve a spectrogram preset choose the name of the preset from the Preset menu When you retrieve a preset all of the spectrogram parame ters in the Configure Spectrogram dialog are immediately set to the saved values If you then change some parameters and want to revert to the saved values click the Reset button or select the name of the preset from the Preset menu again If you want to save changes you ve made under the name of the last preset you loaded choose Preset gt Save Preset Name Spectrograms displayed by Raven have a logarithmic power color axis That is the color by default grayscale values shown in the cells of an unsmoothed spectrogram represent the logarithm of the power at the cor responding frequency for eac
55. playback button 9 Stop Recording button 47 64 Stop Recording to Disk button 64 storage requirements 158 159 support for Raven 48 Swatches color chooser 132 T tags in file name templates 59 technical support 48 3 dB bandwidth See filter bandwidth TIFF graphics file format 45 time analysis resolution 166 167 time domain 162 time grid spacing 83 169 171 172 time grid spacing hop size 82 Time parameter 83 time tags in file name templates 59 time frequency uncertainty principle 166 170 tooltips 4 triangular window function 77 U uncertainty principle See time frequency uncertainty principle Undo Edit menu 35 Unlink View View menu 21 unlinking views 20 21 unrecoverable errors 49 updates software and documentation 140 151 V View menu Choose Measurements 32 Clear Active Selection 30 Clear All Selections 30 Color Scheme gt Colormap name 36 Color Scheme gt Edit 37 131 Color Scheme gt Reverse Color Map 37 Deactivate Selection 30 Delete View 24 Hide View 24 Move View Down 24 Move View Up 24 New gt Similar Selection Spectrum View 128 Raven 1 2 User s Manual New gt Similar Spectrogram Slice View 128 New gt Similar Spectrogram View 128 New gt Spectrogram Slice View 17 Smooth Spectrogram 93 95 Spectrogram Parameters 97 Unlink View 21 Window Preset gt Preset name 42 Window Preset gt Save Preset name 43 Window Preset gt
56. presets on page 41 Raven is installed with a sound window preset named Default which is initially specified as the default by the following entry in the preference file raven preset soundWindow defaultPreset Default To change the default to a different sound window preset edit this entry For example to use a sound window preset called MyWindow by default change the default measurement preset entry to raven preset soundWindow defaultPreset MyWindow A color scheme preset saves the colors of all elements in a color scheme the spectrogram color map and colors of view elements such as position markers selection borders and fills and background under a single pre set name You can retrieve a saved color scheme preset from the Color Scheme gt Preset menu on the View menu or the contextual menu for any view Color scheme presets are discussed further in Color scheme pre sets on page 135 Raven 1 2 User s Manual Default workspace Chapter 6 Preferences Raven is installed with a color scheme preset named Default which is initially specified as the default by the following entry in the preference file raven preset colorScheme defaultPreset Default To change the default to a different color scheme preset edit this entry For example to use a sound window preset called MyColors by default change the default measurement preset entry to raven preset colorScheme defaultPreset MyColors When a window pres
57. recorder window the time axis is by default running recorder zoomed so that the length of the recording buffer just fits in the window The time position location is at the right hand edge of the window As with any other sound window you can zoom and scroll any view in any dimension whether the recorder is running or stopped If you drag the scroll thumb away from the right hand end of the scrollbar while the recorder is running the view stops scrolling and the data remain station ary in the window although acquisition continues without interruption When you release the scroll thumb at any point other than at either end of 66 Raven 1 2 User s Manual Chapter 2 Signal Acquisition Recording the scrollbar the thumb begins to crawl to the left This movement occurs because as the view remains fixed at a particular time its position within the buffer changes as new data are acquired and the oldest data are discarded When the scroll thumb approaches the left edge of the window representing the point at which the oldest data are discarded data begin to disappear from the left hand end of the view and are replaced from left to right by a gray background Selections and editing in a recorder window When a recorder window contains audio data you can create selections whether the recorder is running or stopped You can copy and save selec tions but Cut Delete and Paste operations are prohibited in recorder windows
58. relative to the time scale shown in a view the flickering gray band disappears When it is larger the band becomes more promi nent By specifying a display latency greater than zero you give Raven some additional time to compute a view and build the corresponding image before it needs to be displayed A small display latency e g 0 1 or 0 2 sec onds often eliminates the flickering band with only a barely perceptible delay in the display of real time data Non zero display latencies also result in smoother updates to real time spectrogram slice views The Window Preset drop down list on the Display tab shows the name of the window preset that will be applied to the recorder window when it is first created Window presets define what views are visible in a window as well as window size selection mode and other properties You can choose from all of the window presets that are currently defined by click ing on the drop down menu icon to the right of the Window Preset field Raven 1 2 User s Manual 55 Chapter 2 Signal Acquisition Recording Window presets are discussed further in Using sound window presets in Chapter 1 page 41 File Format The File Format tab appears only if you choose Record to File or Record to File Sequence S Configure New Recorder xj Preset Record To File i Input Display File Format Fi File Format AIFF x Sample Size 16 Y bits File Size 10
59. resume your work later exactly where you left off even if you have many sound windows open with multiple views selections and linkages Raven lets you save the active signal in a sound file either in WAVE format filename extension wav or in AIFF Audio Interchange File Format file name extension aif format WAVE files can be opened by most other programs that work with audio data AIFF files can be opened by most Macintosh programs that work with audio data and some programs on other platforms Files saved in WAVE or AIFF formats contain only the actual audio data Information that is specifically for use with Raven e g selection bound aries spectrograms and linkage information is not saved in these files To save a sound choose File gt Save Sound N or File gt Save Sound N As Choosing Save Sound N simply saves the sound under the same filename in the same location as the last time the sound was saved If the sound has never been saved Raven asks you to specify a location and name for the file Choosing Save Sound N As allows you to specify a new location and or name for the file to be saved The Audio File Format drop down menu in the Save As dialog box allows you to choose a file format WAVE or AIFF and a sample size for the file to be saved Choice of sample size is discussed in Appendix A Digital Representation of Sound Raven 1 2 User s Manual 43 Chapter 1 Gettin
60. rows To highlight a series of contiguous rows click on the row at one end of the series i e the first or last row of the series then shift click on the row at the other end of the series To high light multiple non contiguous rows click on the first row to be high lighted then control click on other rows To clear all selections in a signal choose Clear All Selections from the View menu or from the contextual menu for any view or selection or for any row in the selection table Copying pasting and cloning selection boundaries 108 There are two ways to create a selection that duplicates another selection in frequency boundaries and duration Raven 1 2 User s Manual Creating duplicate selections at different times Cloning selections Selection labels Chapter 4 Selections and Measurements To create a selection identical to the active selection but located at a differ ent time first choose View gt Copy Active Selection Then position the mouse pointer at the point in time where you want the new selection to be centered right click Windows or Ctrl click Mac OS to and choose Paste Selection from the contextual menu To create a duplicate selection that is superimposed upon the active selec tion choose View gt Clone Active Selection The new selection will be acti vated and displayed on top of the previously active selection You can then manipulate the new selection via its control points Using
61. those two will be highlighted and will be shown in the File Name field Each file name in the File Name field will be enclosed in double quotation marks You can type the names of the files that you want to open in the File Names field with each name enclosed in double quotation marks like myFile wav and a space between successive quoted file names Once you have chosen all of the files you want to open click OK Raven 1 2 User s Manual 115 Chapter 5 Advanced Raven Usage LM x Look In C Examples v al E Cy 2000Hz aif 3 CassinsKingbird Audio File Format Bi AfricanF orestElephants aif L ChestnutSidedy4 Type AIFF L BeardedSeal aif C EscreechOw aif LC Bird array 4 channel aif HumanVoice aif Bi BlackCappedvVireo aif D LarkSparrow aif Cy Bluewhale aif Dy Noise aif Eeka T oa ee G BowheadWhaleSong aif Raven aif Length 57 297 seconds Y G CanyonWren wav D RBnuthatch way Channels 1 Sample Rate 11025 Hz Window Preset Default x File Name BeardedSeal aif BowheadhaleSong aif Files of Type All Files x Open Cancel Figure 5 1 The Open Sound Files dialog box with two files selected by control clicking in the file list After you click OK in the Open Sound Files dialog box the Configure New Sound Window dialog box appears Figure 5 2 In the Multiple Files pane at the bottom of the Window tab cl
62. tion or spectrum When the signal and spectrum are represented as a sequence of discrete digital values a version of the Fourier transform called the discrete Fourier transform DFT is used The input to the DFT is a finite sequence of values the amplitude values of the signal sampled digitized at regular intervals The output is a sequence of values specify ing the amplitudes of a sequence of discrete frequency components evenly spaced from 0 Hz to half the sampling frequency Figure B 3 Raven implements the DFT using an algorithm known as the fast Fourier transform FFT Raven 1 2 User s Manual Appendix B Spectrum Analysis gt Time lt T arte paliatre Xo X4 X2 o Xu DFT gt Ao A1 A2 Avia v A Frequenc fo h h fy ee Figure B 3 Schematic representation of the discrete Fourier transform DFT as a black box The input to the DFT is a sequence of digitized amplitude values Xp X4 X2 Xy 1 at N discrete points in time The number of input values N is called the DFT size The output is a sequence of amplitude values Ap Aj Ao Agyzy at N 2 discrete fre quencies The highest frequency fy 2 1 is equal to half the sampling rate 1 2T where T is the sampling period as shown in the figure The output can be plotted as a magnitude spectrum In practice a spectrum is always made over some finite time interval This interval may encompass the full length of
63. to memory see Retroactive Recording Offset on page 71 This feature is useful when acquiring data from field or lab recordings that contain signals of interest interspersed among long segments without such signals For example if you re acquir ing data from a tape recording you might configure a file sequence recorder with a 5 second retroactive recording offset You would then monitor the tape by starting the recorder in record to memory mode and watching real time views as the tape is played back When you see or hear a signal of interest you would click the Record to Disk button Raven Raven 1 2 User s Manual Adjusting recording level Chapter 2 Signal Acquisition Recording would immediately begin acquiring data starting with the last 5 seconds in the recording buffer i e the last five seconds shown in real time views in the recorder window As long as you start the disk recording within 5 sec onds of the start of your signal of interest that signal would be saved to disk In order to avoid distortion in recorded signals it is important to adjust the recording level appropriately You adjust the recording level using controls provided by your operating system as discussed in Appendix C Configuring Audio Input Ideally the level should be adjusted so that the minimum and maximum excursions of the waveform view are close to the vertical limits of the waveform scale without actually reaching those limits
64. yield the element s color Values for red green and blue range between 0 and 255 You can specify RGB values by typing them into their respective fields in the dialog or by sliding the corresponding controls left or right Raven 1 2 User s Manual 133 Chapter 5 Advanced Raven Usage Swatches HSB RGB Figure 5 15 The RGB red green blue color chooser in the Color Scheme Editor dialog box Opacity There is an ordering relationship among the various elements that are dis played in a view such that any one element is either in front of or behind any other element Each element in a view has an opacity associated with it that can vary between 0 and 255 An element that has an opacity of 255 is completely opaque it completely hides whatever elements are behind it An element with an opacity of 0 is completely transparent hence invisi ble An element with an intermediate opacity allows elements behind it to be seen but tinted with the front element s color Figure 5 16 By default Active Selection Fill and Inactive Selection Fill have opacity values of 15 all other elements are completely opaque opacity 255 You can set the opacity of the selected view element by moving the horizontal Opacity slider kHz Figure 5 16 Two spectrogram views showing the effect of varying opacity of the Active Selection Fill color In the upper view the opacity is set to 15 the default value in the lower vie
65. you should always choose plain text or text only b When you edit the preference file make sure that the revised Each particular preference is specified by an entry in the preference file of the general form raven prefName prefValue where prefName is replaced by the name of the particular preference and prefValue is replaced by a valid value for that particular preference For example the entry raven preset colorScheme defaultPreset Default specifies that Raven should by default apply the color scheme preset named Default to new views The character is considered the comment character in the preference file any text that follows this character up until the end of the line is dis regarded by Raven You can thus add comments to a preference file to make it more intelligible to a human by preceding each comment line with The preference file that is supplied as part of the standard Raven installation contains comments that explain the meaning of each prefer ence line You can also comment out an entry and cause Raven to ignore it by inserting at the beginning of the line across two lines of text each entry in the actual preference b Although some preference entries are shown in this manual file must be on a single line The sections below describe each category of preference in detail 144 Presets provide a mechanism for saving sets of related configura
66. your particular application For many applications Raven s default window size 512 samples provides a reasonable balance between time and fre quency resolution If you need to observe very short events or rapid changes in the signal a shorter window may be better if precise frequency representation is more important a longer window may be better If you need better time and frequency resolution than you can achieve in one spectrogram you may need to make two spectrograms a wide band spec trogram with a small window for making precise time measurements and a narrow band spectrogram with a larger window for precise frequency measurements Time grid spacing also called hop size is the time between the beginnings of successive records In an unsmoothed spectrogram this interval is visi ble as the width of the individual boxes Figure B 6 Successive records that are analyzed may be overlapping positive overlap contiguous zero overlap or discontiguous negative overlap Overlap between records is usually expressed as a percentage of the record length Figure B 8 illustrates the different effects of changes to record length and time grid spacing The signal is a frequency modulated tone that sweeps upward in frequency from 4 to 6 kHz sampled at 22 05 kHz Spectro grams a and c both have a record length of 512 points 23 2 mS 3 dB bandwidth 61 9 Hz a was made with 0 overlap time grid spacing 23 2 mS whereas
67. 0 annotations 99 creating 100 deleting 100 entering values 100 101 Fill Down 101 naming 100 renaming 100 anti aliasing filter 156 audio file formats 43 Audio Format Not Supported error 71 audio input configuring under Mac OS 181 configuring under Windows 179 181 audio input device choosing 45 audio input device plug in 52 audio input plug ins 154 Auto apply checkbox in Color Scheme Editor 135 in Configure New Spectrogram dialog box 87 in Configure Spectrogram dialog box 80 Averaging parameter 85 87 axis units 6 visibility and window presets 42 B bandpass filters simulated by STFT 166 173 175 bandwidth 166 Bartlett window function 77 Raven 1 2 User s Manual Begin Time measurement 32 110 111 Beta Kaiser window parameter 80 bit depth 157 158 Blackman window function 77 BMP graphics file format 45 brightness spectrogram 7 88 90 133 and window presets 42 bug reports 48 C ceiling color 89 90 ceiling value 89 90 Center Position button 11 13 Channel Visibilities as linkable properties 23 channels hiding 124 showing 124 Channels list side panel 124 Choose Measurements View menu 32 Clear Active Selection View menu 30 Clear All Selections View menu 30 Clear Selection N selection contextual menu 30 clipping during recording 65 66 Collapse Selection Table button 31 color choosers 132 HSB 133 RGB 133 134 Swatches 132 Color Scheme
68. 0 seconds Advanced Cancel Figure 2 3 The File Format tab of the Configure New Recorder dialog box File Format Raven can acquire audio data directly to files saved either in AIFF Audio Interchange File Format filename extension aif or in WAVE format filename extension wav WAVE files can be opened by most other pro grams that work with audio data AIFF files can be opened by most Mac intosh programs that work with audio data and some programs on other platforms 56 Raven 1 2 User s Manual Sample Size File Size File naming Chapter 2 Signal Acquisition Recording The Sample Size parameter specifies the bit depth of the samples saved in the file s created during signal acquisition Raven always represents signals internally with 16 bits per sample If you choose an output sample size other than 16 bits the data values are rescaled to the specified sample size See Appendix A Digital Representation of Sound for a discussion of the trade offs involved in choice of sample size The size of the file s to be saved can be specified either in time units sec onds or minutes storage units kilobytes or megabytes or sample frames A sample frame consists of one sample for each channel in the acquired signal For example if you specify a file size of 100 000 sample frames for a signal acquired at a sampling rate of 22 050 Hz each acquired file would be 4 535 seconds long 4 535 100 000 sample
69. 1 Hop size was called time grid spacing in versions prior to Raven 1 2 Raven 1 2 User s Manual Chapter 3 Spectrographic Analysis overlap or separated by time intervals that are omitted from the analysis negative overlap Window overlap is usually expressed as percent of window size For example an overlap of 50 means that each window begins halfway through the preceding window An overlap of 100 means that one win dow of data is skipped between successive windows that are analyzed 300 skips three frames and so on The relationship between hop size and window overlap is given by hop size window size 100 overlap The Hop Size and Overlap fields in the dialog box are coupled so that you can specify hop size either directly by typing a value in the Hop Size field or indirectly by typing a value in the Overlap field Using the units drop down menu you can specify the measurement units for hop size as either samples the default seconds or milliseconds If you enter a value in the Overlap field that does not correspond to an integer number of samples Raven substitutes the closest overlap value that does Figure 3 10 shows three spectrograms that differ only in hop size Raven 1 2 User s Manual 83 Chapter 3 Spectrographic Analysis 84 Pilly Frequency grid spacing and DFT size a 4 6 4 kHz b 6 4 kHz 6 4 J kHz S 0 1 0 2 0 3 0 4 Figure 3 10 Effect of va
70. 1 page 37 S Configure iew Axes x Time Position loo00 Seconds Scale 6 477 Seconds Line Frequency Position 10 0 Hertz Scale 22050 0 Hertz Line Zi auto apply ok Apply Reset Close Figure 5 10 The Configure View Axes dialog box for a spectrogram view Creating linked spectrographic views To create a new spectrogram spectrogram slice or selection spectrum view that is linked by spectrogram parameters to an existing spectro graphic view choose New gt Similar Spectrogram View New gt Similar Spectrogram Slice View or New gt Similar Selection Spectrum View from the contextual menu for any spectrographic view or from the View menu for the active spectrographic view Filtering and amplifying sounds 128 Filtering Raven allows you to filter out or filter around a selected frequency band in a sound When you filter out a frequency band frequency components in that band are removed from the signal When you filter around a fre quency band frequency components outside of that band are removed leaving only the frequencies in the selected band The filtering operation can be performed on the entire signal or on a time interval that you select Raven 1 2 User s Manual Chapter 5 Advanced Raven Usage To filter out or around a particular frequency band make a spectrogram of the sound and then use the mouse to select the frequency band to be fil tered To filt
71. 3 50 0 00 kHz0 000 0 500 1 000 1 500 2 000 2 500 Figure 1 25 Point selections in green as they appear in different view types Time positions of all three views are linked to each other Selection 1 was created by clicking in the waveform Selection 2 was created by clicking in the spectrogram Selections 1 and 2 are not visi ble in the spectrogram slice view because the time position is not at the time of either selection Selection 3 was made by clicking in the spec trogram slice view In the waveform selection 3 is hidden behind the time position marker Deactivating and To deactivate the active selection choose Deactivate Selection from the clearing selections selection s contextual menu or activate another selection To remove the active selection choose Clear Active Selection from the selection s contex tual menu To remove an inactive selection choose Clear Selection N from the selection s contextual menu You can also remove all selections by choosing Clear All Selections either from the View menu or from the con textual menu for any selection To clear a selection means to remove the selection leaving 3 the data in it untouched To delete a selection means to delete the data identified by that selection in the process the selection itself is cleared The Selection Table At the bottom of each sound window is a selection table which by default is 30 collapsed so that it
72. Appendix B Spectrum Analysis trogram on a grid with finer frequency resolution smaller frequency bins vertically smaller boxes The number of frequency bins in a spectrogram or spectrum is half the DFT size plus one Recall that the DFT size is the number of samples processed to calculate the spectrum of a record Thus the DFT size would ordinarily be equal to the record length However Raven s DFT algorithm requires that the size of the DFT be a power of 2 Therefore Raven automatically chooses the smallest DFT size that is a power of 2 greater than or equal to the record size The sample data in each record are then filled out with zeros zero padded to make the record length the same as the chosen DFT size Zero padding provides the right number of samples to match the chosen DFT size without altering the spectrum of the data The spectra that constitute a spectrogram produced by a STFT are imper fect in several respects First as discussed above each filter simulated by the STFT has a finite band of frequencies to which it responds the filter is unable to discriminate different frequencies within this band According to the uncertainty principle the filter bandwidth can be reduced thus improving frequency resolution only by analyzing a longer record which reduces temporal resolution Second the passbands of adjacent filters overlap in frequency so that some frequencies are passed though partially attenuated
73. Clicking Reclaim will force Raven to display the most up to date possible data on memory usage Raven program and documentation updates 140 From time to time the Raven development team releases software and documentation updates that fix errors in Raven or the Raven User s Man ual By default Raven will automatically attempt to contact the Raven update server via the Internet to see if any new update files are available each time you start the program If updates are found Raven will display a dialog showing how many update files are available and their total size Figure 5 19 You can then choose whether or not to download the Raven 1 2 User s Manual Chapter 5 Advanced Raven Usage updates Separate dialogs are shown for program files and documentation files If you choose not to download update files you can always down load them later You can check for updates at any time by choosing Help gt Check for Updates Download Raven program updates x There are 2 updated program files to download The download size is 2 3 KB For a full description of the updates please visit http iwww birds cornell edu brp raven updates Do you want to download these updates now Figure 5 19 The download update files dialog There is no separate installation procedure required once the update files have been downloaded but you need to restart Raven for the updates to take effect If you do not restart immediately the
74. Editor 131 134 color scheme presets default 146 color schemes 36 37 129 135 and window presets 42 as linkable properties 23 Auto apply checkbox 135 brightness 133 color choosers 132 133 editing 37 129 135 elements 130 HSB color chooser 133 hue 133 opacity 134 presets 135 RGB color chooser 133 134 saturation 133 Swatches color chooser 132 colormap See spectrogram colormap 183 Index Command backspace 34 Command L 17 Command O 1 8 Command R 46 Command shift Z 35 Command Z 35 Components pane side panel 25 components window 25 Configure New Recorder dialog box 46 Advanced button 68 70 Buffer Size parameter 54 Channels checkboxes 53 Device drop down list 52 Directory parameter 58 Display tab 54 56 File Format tab 56 File Name tab 57 File Names tab 57 61 File Size parameter 57 Input tab 52 53 Latency parameter 55 Rate Conversion tab 70 recorder presets 62 Retroactive Recording Offset parameter 64 71 Sample Format drop down list 53 Sample Rate drop down list 53 Sample Size parameter 57 Schedule tab 70 Simple button 68 70 Sound File s parameter 58 Speed tab 68 Start Time parameter 60 Update Rate parameter 54 Window Preset drop down list 55 Configure New Sound Window dialog box 42 118 120 121 Configure New Spectrogram dialog box 78 80 82 84 87 88 3 dB bandwidth 80 Apply button 87 Auto apply checkbox 87 Averaging parameter 85 87
75. FEQUENCY ttn sedeciea ase atahe eed od ded awtals Ue ee eae EEEREN E 150 Amplitude keser cee ce aa et eatin te buen duces abe rie eres eae eee aa te 150 POWE Sis 0 pnabvna dna Maa ted tier d e PRdie Me ede PA E E one dando E maids 150 Overwrite behavior for recorders ccc cece cee eee e eee eees 151 Automatic updates seron ak Ae eee eee De pe eae 151 Email PreferenGes lt sdoue espace sides Sls Wald ante sw ae GES a Win Wawa we NS 151 Returm address oee srr eitea Gaede Padua pe locate Ee ee EERTE esata 151 Outgoing malser oaaae are ne SPE ee eee ees 151 Appendix G Digital Representation of Sound 153 Ab tthis appendiks ssns iy n aa a a eto 153 Digital sampling srie E cakes wae IA E E aa E eka 153 Sampling tate hook ie h a E DENE E AE EE E E E Gs yokes 154 Aliasing and the Nyquist frequency 0 00 cee ee 154 Sample size amplitude resolution 0 cece eee cee eee eens 157 Specifying sample sizes when acquiring and saving signals 158 Storage reguirementS isi inne sad vals eee eee a a das lores Maw ele be 158 vi Raven 1 2 User s Manual AppendixH A Biologist s Introduction to SPSCHUMAIIALY SISA wy a n Meet Shen eae ta ornare 161 About this appendix inci Pin ew ew wee egiew aorta waws aly sass cae owe das 161 WhalsOundis rss cw dreni a typos ies A eee Hs ee ee eee ew 161 Time domain and frequency domain representations of sound 162 Spectral analysis of
76. I 81 Time grid Window Overlap and EEN AE E ere ht te ele E E E E E E OE E E ATE S 82 Lock Overlap vs Lock Hop Size 0 0000 cette 84 Frequency grid spacing and DFT size 0 ee ee 84 LOCK DET SIZG oii shih enti ee ed ace ire DE A E 85 Spectrum averaging 0 cc tees 85 Apply and Auto apply 000 000 87 Spectrogram presets scoite pa ae E a en e Pya AN a tees 88 Spectr graMmi VieWS ueser i n s E awe E a 88 Significance of the color grayscale values 0 6 2 0 0 00 ee 88 Brightness and contrast 2 0 eee eee 88 Time alignment of spectrogram data 0 0 0 cee ee 90 Smoothed vs unsmoothed display 0 0 c eee eee 92 Spectrogram slice Views nu is cin ees oe tines da eee ee whee ness 95 Time position of a spectrogram slice view 0202 cence eee 95 Significance of the spectrum values 0000 cee eee 96 Selection spectrum Views 4 tik iwc s ewes vweupe eee woh yad deus neta 97 Significance of the spectrum values 0000 cee ae 97 Changing parameters for an existing spectrographic view 97 Selections and Measurements 005 99 About this chapteterc sas its anaa arere veiw ee eels beets ead 99 PROANOLATLONG aos 9 55 4 ad wc 9 80s oe Aad Dagon AE PO A ws Rl A A ae E 99 Creating renaming and deleting annotation columns 100 Entering annotations asi dean arenen a oie cag deeds Med la ede g odin dey 100 Ente
77. Il dd hh mm Figure 2 5 The File Names tab of the Configure New Recorder dialog box When you record to a file sequence Raven saves the incoming audio data to a continuous series of files as described in File Format on page 56 and File naming on page 57 In addition Raven saves a list file which is a plain text file containing a list of all of the audio files recorded in the file sequence Once an audio file sequence and its associated list file have been created you can open the sequence as a single signal by opening the list file Opening a file sequence via a list file is discussed in Opening file sequences in Chapter 5 page 117 Raven 1 2 User s Manual 61 Chapter 2 Signal Acquisition Recording A list file must always reside in the same directory as the audio files in the file sequence that it lists occur while acquiring to a file sequence the list file and some of the acquired audio files can end up in different directories If Raven has warned you of such collision events you may need to manually move some files in order to have the list and audio files in the same directory b If file name collisions see File name collisions on page 60 Using recorder presets 62 You can use recorder presets to save and retrieve sets of parameters for the entire recorder dialog and for each tab within the dialog To save a recorder preset for the entire dialog including parameters
78. Raven 1 2 User s Manual Revision 1 10 November 2004 HOLOGY ROGRAM This manual can be printed or used online To access all online fea tures we recommend viewing with the latest version of Adobe Acrobat Reader available free at For online viewing use the bookmarks in the navigation pane on the left to navigate to sec tions within the manual Cross references in the text and index entries are hypertext links click the link to view the referenced section or page Copyright notice Raven software the Raven 1 2 User s Manual and example sounds Copyright 2003 Cornell Lab of Orni thology All rights reserved Reproduction of any part of this work in any form without permission is pro hibited The Raven software includes code licensed from RSA Security Inc Some portions licensed from IBM are available at http oss software ibm com icu4j Trademarks Microsoft and Windows are registered trademarks of Microsoft Corporation in the United States and or other countries Mac and Mac OS are registered trademarks of Apple Computer Inc PostScript is a regis tered trademark of Adobe Systems Inc Java is a registered trademark of Sun Microsystems Inc Other brands are trademarks of their respective holders and should be noted as such Mention of specific software or hardware products in this manual is for informational purposes only and does not imply endorsement or recommendation of any product Cornell Univer
79. To record or play back sounds with more than two channels you need to have a multi channel sound card installed in your computer The Examples directory that is installed with Raven includes a 4 channel file named Bird array 4 channel aif that you can open to see how the features described below work Displaying and The Layout tab of Raven s side panel contains a Channels pane that lists all hiding channels of the channels of the active sound window Figure 5 7 Each channel is identified by a number A checkbox next to each channel number controls whether that channel is visible in the sound window To display or hide a channel turn the checkbox on or off by clicking on it You can display or hide all channels in a sound at once by clicking the Show All or Hide All icon above the checkboxes Figure 5 7 124 Raven 1 2 User s Manual Chapter 5 Advanced Raven Usage Show all Hide all H H Channels IS IS ISI S J ara Figure 5 7 The Channels pane on the Layout tab of Raven s side panel Editing multi Each channel of a multi channel sound must be exactly the same length channel sounds i e must contain the same number of samples as every other channel in the sound Therefore editing operations that change the length of a sound Cut Paste and Delete always apply to all channels in a sound Editing operations that do not change the length of a sound Copy Filter and Amplify can apply t
80. You can specify the size of the buffer in seconds when you configure a recorder During recording audio data are stored in the buffer until the buffer is full and then the oldest data are continually discarded to make room for new data being acquired For example if the buffer size is 30 seconds the default the buffer will always contain the most recent 30 seconds of data during recording data recorded more than 30 seconds ago are lost While a signal is in the recording buffer you can manually save it to a disk file or save selections from it Recording to memory is useful for exploratory browsing through recordings when you don t need to save the data to files or when the signals you re interested in saving are sparsely distributed among sections that you don t want to save Raven 1 2 User s Manual 51 Chapter 2 Signal Acquisition Recording Creating a recorder Recording Input e Record to file When recording to a single file Raven saves audio data directly to a disk file for a specified amount of time then stops You can also manually stop recording to disk before the specified time has fin ished e Record to file sequence When recording to a file sequence Raven saves audio data continuously to a series of files each of which is a specified size Successive files in a sequence are named according to a template that you specify which can incorporate a sequence number or a times tamp Raven also saves a l
81. a sound window that contains selections at times later than the time where the editing operation is performed those selections will no longer refer to the same data as they did before the editing operation b In Raven 1 2 if you perform Cut Paste or Delete operations The most recent change to a sound window can be undone by choosing Edit gt Undo or by typing lt Ctrl Z gt Windows or lt Command Z gt Mac OS By repeatedly using the Undo command you can undo multiple changes from most to least recent You can redo a change you ve undone by choos ing Edit gt Redo or by typing lt Ctrl shift Z gt Windows or lt Command shift Z gt Mac OS You can redo one at a time as many changes as you ve undone Raven enables you to selectively filter out all energy in particular fre quency bands of a selection or an entire sound window You can also amplify all or part of a sound by any specified factor including factors less than 1 Amplifying by a factor less than 1 attenuates the sound Filtering Raven 1 2 User s Manual 35 Chapter 1 Getting Started Color schemes and amplification are discussed in Filtering and amplifying sounds in Chapter 5 page 128 36 Spectrogram colormaps Each view in a sound window has a particular color scheme A color scheme consists of a spectrogram colormap and particular colors for items such as active and inactive selection borders and fills dots and lines in wavefo
82. acquiring input 0 cece cece cee ee eee 45 Selecting an audio input device 0 0 eae 45 The Configure New Recorder dialog Dox 0 eee eee 46 The Recorder Window 0 00 0 eee tee eae 46 Starting and stopping the real time signal display 0000 47 Displaying real time spectrograms and spectrogram slices 47 Other operations while recording 000 e eee eae 48 While recording is stopped 000 200s 48 More about recording reator ccc eee 48 Contacting the Raven development and support team 48 Signal Acquisition Recording 51 About this chaptet jj0s cis c eves ties ctf eimue sc nase eee ease ta s 51 Overview of signal acquisition ccc eee cee cece eee eee eee 51 Recording MODES serra Bic caste stevens hin ele aah Ra lesa ese Re eR Ga RS 51 Creating a recorder crinca a ea a tees 52 Raven 1 2 User s Manual Chapter 3 Recording Inpulvsscaciecin ds rena eiee se eee esata eae ee eae 52 BE E E ag gested aden weal eget vee alate BER Leen ean ed 52 SaMplesRate s eg naei Hoan we aed akaa Mine aaa D Batak aa it alae ind a a tian 53 ChannelStacccucakica bce gacd acs tiga bales oo tearha lad ead mens es 53 Sample Formats tee ee sated e tha toate t waa hls oda tee alee te hea weed 53 Recording Displays oreesa sg ad tae eee E caw ae eda aw ews 54 Butter SIZ6 ec lg etc a Eola eagle E aul OF dee esheee 54 Update R
83. agnifi cations The signal is a song of a chestnut sided warbler Both views are made with a 512 sample Hann window and 50 overlap The upper view shows the entire song the lower view is zoomed to the selection The individual spectrogram cells are clearly visible in the lower panel In a smoothed spectrogram the color of each individual display pixel is determined by bilinear interpolation between the power values calculated at the grid points i e the centers of the boxes shown in an unsmoothed spectrogram Each time the spectrogram is resized the color values for individual pixels are recalculated Thus no matter how much you stretch a smoothed spectrogram you will not see sharp edged boxes as you would with an unsmoothed spectrogram In a smoothed spectrogram the no data color is displayed before the time of the first spectrum and after the time of the last spectrum because Raven cannot interpolate power values beyond these points Spectrogram smoothing is not a substitute for the finer spectrogram grid resolution obtained by increasing the window overlap and DFT size how ever Both may make a spectrogram more esthetically pleasing but only finer grid resolution will reveal some structural details of the signal that are invisible in a low resolution spectrogram Figure 3 18 Raven 1 2 User s Manual Chapter 3 Spectrographic Analysis Figure 3 18 Difference between smoothed spectrogram calculated on
84. all squares that you can grab and move with the mouse to adjust the boundaries of the selection or move the selection Figure 1 23 When you move the mouse pointer over a selection control point the mouse pointer changes to an icon indicating the directions that you can move that control point At any given time one control point may be active The active control point is shown as a solid square inactive control points are shown as open squares For example the bottom right control point in Figure 1 23 is active the others are inactive The active control point can be moved using the arrow keys on the keyboard To activate a selection control point click on it Once one of a selection s control points is active you can activate successive control points for that selection by repeatedly pressing the lt Tab gt key Whenever the mouse is over a view containing an active selection one of the selection control points called the extender point will be displayed at a slightly larger size than the others The extender point is always the closest control point to the current position of the mouse pointer For example in Figure 1 23 the upper right corner control point is the extender point You can move the extender point to a new location in a view by shift clicking at that location Raven 1 2 User s Manual 27 Chapter 1 Getting Started 28 4 Sound 4 ChestnutSidedWarbler aif Ola nS DIODE Figure 1 23 An active uncom
85. am If Raven encounters an unrecoverable error it will ask if you want to submit a bug report If you report the bug using Raven s email feedback form Raven will include information along with your message that can help us find the cause of the problem and correct it in future versions You can see the additional information that Raven includes if you look in the Context tab If you send your message from another program this information will not be included y Email Feedback S xj File Insert To GCs From yourEmailAddress yourlSP Category Bug Report ai Subject Figure 1 35 The Raven email feedback dialog If for some reason you are unable to send feedback when you want to do so for example because your computer is not connected to the Internet at the time or there is an unexpected problem transmitting the message you can choose File gt Save As to save a feedback file to be sent later To send the feedback file later do one of the following e Choose File gt Open in the Raven Email Feedback dialog box to open the saved feedback file then click Send e Send a message to from your regular email program to raven bugs cornell eduor raven_support cornell edu and include the saved feedback file as an attachment Raven 1 2 User s Manual 49 Chapter 1 Getting Started 50 Raven 1 2 User s Manual Chapter 2 About this chapter Signal Ac
86. anipu lated or analyzed with a digital computer the signal must be acquired or digitized by a hardware device called an analog to digital A D converter or digitizer The digitizer repeatedly measures or samples the instantaneous voltage amplitude of a continuously varying analog input signal at a particular sampling rate typically thousands or tens of thousands of times per second Figure A 1 In the case of an audio signal this time varying voltage is proportional to the sound pressure at a device such as a micro phone The digital representation of a signal created by the digitizer thus consists of a sequence of numeric values representing the amplitude of the original waveform at discrete evenly spaced points in time Amplitude gt lt Time At Figure A 1 Sampling to create digital representation of a pure tone signal The blue sinusoidal curve represents the continuous analog waveform being sampled Measurements of the instantaneous ampli tude of the signal are taken at a sampling rate of 1 At The resulting sequence of amplitude values is the digitized signal The precision with which the digitized signal represents the continuous signal depends on two parameters of the digitizing process the rate at which amplitude measurements are made the sampling rate or sampling Raven 1 2 User s Manual 153 Appendix A Digital Representation of Sound Sampling rate frequency and the number of bits used to represent each a
87. annels Sample Format Chapter 2 Signal Acquisition Recording default audio input device typically a built in sound card for your com puter The audio input device obtains its input from a recording source that you choose using controls supplied by your computer s operating system Appendix C Configuring Audio Input explains how to configure your operating system s controls to choose a recording source e g the com puter s built in CD player a microphone or line input jack for audio input Each audio input device is characterized by a set of available sampling rates at which signals can be recorded the number of channels that can be recorded and a set of sample formats Each of these parameters is dis cussed below Some devices may also have additional parameters that can be configured The Sample Rate drop down list displays all of the sampling rates avail able for the selected input device Typically the sampling rates available are determined by the underlying sound input hardware The Sample Rate parameter specifies the rate at which an analog electrical signal rep resenting a sound is sampled to create the digital signal Be sure to choose a sampling rate that is at least twice as high as the highest frequency in the recording you want to acquire in order to avoid signal distortion due to aliasing See Appendix A Digital Representation of Sound for a discus sion of aliasing and the trade offs involved
88. ar in a wave form or spectrogram view corresponds to the total duration of the sound that is in Raven s working memory The length of a scrollbar s scroll thumb Figure 1 4 page 5 Figure 1 5 page 6 relative to the length of the entire scrollbar indicates what proportion of the corresponding axis is vis ible in the view pane When the entire axis is visible the scroll thumb is half the length of the scrollbar as in Figure 1 4 and Figure 1 5 The location of the scroll thumb within the scrollbar indicates the view s position relative to the data When the horizontal scroll thumb of a wave form or spectrogram is at the left edge of the scrollbar the start of the data is aligned with the position marker Figure 1 10 when the box is all the way to the right the end of the data is aligned with the position marker Raven displays a gray background for areas in each view pane that are beyond the limits of the data for example before or after the beginning or end of a signal in the time dimension 1 The one exception is when you try to drag the position marker beyond the lim its of the signal In that case the end point of the signal will move with the marker and you will be changing the position location but not the position which is set to one of its limits already 2 If you opened the entire sound at once the default the duration of the sound in memory is the duration of the entire sound file or file
89. arted directory in the scrolling list of files and directories within the current directory On Windows computers the Audio File Format panel WINDOWS onthe right side of the Open Sound Files dialog box displays information about the currently selected file Select the file named ChestnutSidedWarbler aif in the Examples direc tory Click the Open button or double click on the file s name The Con figure New Sound Window dialog box appears Figure 1 3 The Configure New Sound Window dialog box allows you to choose a win dow preset that controls the layout of a sound window discussed in Using sound window presets on page 41 and to control how much of the sound is loaded into Raven s working memory at one time see Paged sound windows opening large sounds in Chapter 5 page 120 For now click OK to accept the default settings A sound window appears on the Raven desktop Figure 1 4 The title bar of the sound window shows a sequential number starting at 1 that Raven assigns to each sound you open and the name of the file S Configure New Sound Window i x Window Speed Preset Default v Paging Open entire sound Page sound Figure 1 3 The Configure New Sound Window dialog box Raven 1 2 User s Manual 3 Chapter 1 Getting Started The Raven window When Raven is running you can open any WAVE or AIFF 3 sound file by dragging its icon from an
90. as well r Sound 1 ChestnutSidedWarbler aif Waveform 1 OO oe Figure 1 22 A sound window showing a waveform and a spectrogram view with line titles displayed Selections and measurements About selections A selection is a specified portion of a signal with a start time and duration and a lower and upper frequency You can define a selection by clicking and dragging the mouse across part of a view Other ways of defining and modifying selections are discussed below Selections are shown in views by colored rectangles In earlier sections of this chapter you have seen how to select part of a waveform or spectrogram and play or zoom to that selection Selections are also used to identify parts of signals that you want to measure edit or save Selections can either be range selections or point selections A range selection identifies a continuous range of times and or frequencies A point selec tion identifies a single point in time and optionally a single frequency You can define range or point selections in any type of view Although you initially define a selection in a particular view selections are associated with a sound not with any particu lar view and are displayed in all views 26 Raven 1 2 User s Manual Chapter 1 Getting Started Creating and There are two ways to create a range selection One way which you ve modifying range already seen is to click and drag the mouse pointer acros
91. ase spectrum 163 164 Play button 8 playback rate 10 Playback tab side panel 8 playing a sound 8 PNG graphics file format 45 point selections 26 29 portrait orientation for printing 44 position of a view 10 11 setting 128 vs position location 13 position location 13 vs position 13 position markers 9 10 14 visibility and window presets 42 preference file 143 144 preferences 143 151 default directories 148 default measurement precision 148 150 default presets 144 146 email 151 overwriting files during acquisition 151 updates software and documentation 151 Preset Manager 135 Preset menu See presets 88 presets Audio File Format 136 Audio File Names 136 Audio Recorder 136 Audio Recorder Display 136 187 Index Audio Recorder Input 136 Audio Recorder Schedule 136 Color Scheme 136 color scheme 135 measurement 103 Measurement List 136 recorder 62 Sample Rate Conversion 136 Selection Labels 136 Sound Window 136 spectrogram 88 Spectrogram Parameters 136 types 136 window 41 42 window precedence over other presets 43 print orientation 44 printing 44 progress bar 63 64 Pulse Code Modulation PCM 53 Q quantization noise 157 R range selections 26 27 Rate Conversion tab Configure New Recorder dia log box 70 Raven desktop 4 6 Raven window 4 6 8 RavenPreferences txt file See preference file real time views during signal acquisition 47 spectr
92. at the frequency scales of spectrogram and spectrogram slice views are rotated 90 from each other Unlinking and linking views Unlinking a view via 20 the contextual menu Two views that share a dimension such as time or frequency can have their positions and scales either linked or unlinked by that dimension When the positions of two views are linked moving the position of either one by moving the corresponding scroll thumb or by moving the position marker within the window causes the positions of both views to move together When the scales of two views are linked changing the scale of either one using the zoom buttons causes both views to be re scaled In the examples you ve seen so far waveform and spectrogram views have been linked by time position and in time scale When you open or record a signal and create multiple views each view is initially linked in position and scale to every other view that shares its dimensions For example waveforms and spectrograms are initially all linked to each other in time position and time scale and spectrogram and spectrogram slice views are linked in frequency position and frequency scale Spectrograms and waveforms cannot be linked in frequency because waveforms have no frequency dimension In some situations it can be useful to work with views that are unlinked from each other in particular ways For example Figure 1 17 shows two spectrogram views of a signal that i
93. ate If you save a file after applying a speed correction it is saved with the new corrected sam ple rate The next time the file is opened either by Raven or any other pro gram its speed will be correct without any adjustment a single file not a sequence in its entirety not in a paged sound window For file sequences you must either apply the correction each time you open the sequence or else open and save each individual file once with a speed correction For files that are too large to open in unpaged windows you must apply the speed correction each time you open the file b In order to save a file with a corrected speed you must open Raven 1 2 User s Manual 127 Chapter 5 Advanced Raven Usage Setting the scale and position of view axes The scale and position of the horizontal and vertical axes of any view can be changed using the zoom controls and scrollbars as described in Changing the position and scale of a view zooming in Chapter 1 page 10 More precise control of scale and position is available in the Configure View Axes dialog box Figure 5 10 To display the Configure View Axes dialog box choose Configure View Axes from the contextual menu for any view or from the View menu for the active view You can enter precise val ues for the position and scale of the view s horizontal and vertical axes Scale is specified in units per line of the view see Multiple line views in Chapter
94. ates a Sites hn E a OA Bik et ela 54 LAENI eae a ero OE So EO 55 Display latency vs processing latency 0 0 00 c eee 55 Window preset o se ccrand Seia cee eee 55 File FOPMAG oo eere aa a Ei E aE EA le EE A E E 56 Fle Fama sekre Geko EEE E EEE E EER EAL ERE h NEEE 56 Sample Size se wed ea a a aa aa a a a ge o a a a aA 57 FIC SZO reai eT E ARERIA A ANE ewe EREE dad BA AER pale Nie 57 Pile NAM cesas teener a e E ee eee eee tea Aa 57 Direc ernaar EEE EDANA E Rated PALEE eae es 58 Sound FOl herrea bane p ar ae Ea aae E DE Bene Weed AE 58 Slant N EE ETE EEEE EA TE aces TTET EET he ee tiga dees shes 60 File name collisions teke pirne o ee ee E TEDRE 60 Recording to a file sequence cc cece cece eee e cece eee eeee ees 61 Using recorder presets ixijouci seri arer te cee iste eles hides ed es 62 The recorder window real time views during recording 63 Creating real time signal ViewS 0 0 00 cee eae 63 Recording to MeMOry 2 0 0 ore eee ee eee eee eee 64 Recording to TileS s 6 wes ku gad See Mi pace ape ga ba eee pe ARITE TOAFA 64 Retroactive recording to fileS 0 0 cece tees 64 Adjusting recording level 0 0 0 c cette eee 65 Navigating and selecting data in a running recorder 000 eae 66 Zooming and Scrolling erase p 00 ce 66 Selections and editing in a recorder windoW 0000e eee e nee 67 Reconfiguring an existing recorder 1 0 0 ce ees 67 Reconfiguring w
95. aximum Heap Size is the largest amount of memory that the JVM will attempt to allocate to the heap e Current Heap Size is the current size of the heap that has been allocated by the JVM to Raven Each time Raven needs more memory than it has available the Current Heap Size increases as the JVM allocates succes sive increments of memory to the heap e Memory Used is the amount of the current heap that Raven is actually using e Memory Available is the amount of Raven s current heap that is not presently in use Memory Available is equal to Current Heap Size minus Memory Used Configuring Maximum Heap Size You can change the maximum heap size by clicking the Configure button in the Memory Manager window Figure 5 18 and entering a new maxi mum heap size in the Configure Maximum Heap Size dialog box that appears In order for the new maximum heap size to take effect you must restart Raven If you do not restart immediately the change will take effect the next time you start Raven the largest value that the JVM will attempt to allocate to the heap The largest heap size that actually can be allocated may be less than the Maximum Heap Size shown if there is not enough memory available that is not being used by other programs including the operating system or if there is insuf ficient physical memory installed in the computer b The Maximum Heap Size shown in the Memory Manager is The memory usage list The b
96. c rmsAmplitude default ValueFormat 0 000 Power To specify the default measurement display precision for power measure 150 ments uncomment and edit the following entry Raven 1 2 User s Manual Chapter 6 Preferences raven measurement basic power defaultValue Format 0 000 Overwrite behavior for recorders Automatic updates You can specify a preference for what Raven should do when recording to files if a new sound file has the same name as an existing file in the selected recording directory by editing the following entry raven ui audioRecorder overwriteExistingFiles false When this preference is set to fal se the default when Raven is installed Raven will create a new directory for the new file rather than overwriting the existing file as described in File name collisions in Chapter 2 page 60 If you change the preference to true the new file will replace the old file without any warning Email preferences By default Raven automatically checks for software and documentation updates each time it is launched To disable this behavior edit the follow ing entry changing its value to false raven updates automatic true Program and documentation updates are discussed further in Raven pro gram and documentation updates in Chapter 5 page 140 Return address Outgoing mail server In order to use Raven s built in email feedback feature see Con
97. cloning to segment a sound You can use cloning to segment a sound into a series of contiguous selec tions by the following procedure 1 Create the first selection in a series either in a waveform or spectro gram view 2 Clone the selection as described above 3 Drag the new selection s left edge to the right past the selection s right edge to the end time of the second selection in the series The edge that initially defined the end of the selection now defines its start which is at the same time as the end of the first selection The edge that origi nally defined the start now defines its end 4 Clone the second selection and then repeat step 3 as needed By default Raven displays each selection s ID number in selection labels in views To toggle display of selection labels on and off use the checkbox in the component list of the side panel s Layout tab Figure 1 20 page 25 Selection labels can display selection IDs and or any combination of mea surements or annotations that are shown in the selection table To choose which measurements are included in selection labels as well as specifying font size and a string to use as a separator between items in selection labels choose Configure Selection Labels from the View menu or any view s contextual menu To add a measurement or annotation to selection labels highlight that item s name in the list of Available Items and click the left pointing arrow button in t
98. configured for recording to file s with a 30 second recording buffer You can create a new view in a recorder window any time whether the recorder is running or stopped If a recorder window already contains multiple views particularly if they are displayed at a large size Raven s responsiveness to keyboard and mouse activity may slow down notice ably on slower computers while the recorder is running In such cases it Raven 1 2 User s Manual 63 Chapter 2 Signal Acquisition Recording 64 Recording to memory Recording to files Retroactive recording to files may be preferable to create new spectrogram or spectrogram slice views while the recorder is stopped To begin recording to memory click the Record to Memory button at the bottom of the window Data begin appearing at the right edge of the win dow where the position marker is located by default in a recorder win dow and scroll across from right to left in all of the waveform and spectrogram views that are displayed If data do not start appearing in the recorder window refer to Problems with recording on page 71 To stop recording click the square green Stop Recording button that replaces the Record to Memory button Each time you start recording any data already in the record ing buffer are erased Raven always records to memory when recording to a file or file sequence so that the recorder window can display real time views during ac
99. ctive Selection from the View menu or the contex Raven 1 2 User s Manual 105 Chapter 4 Selections and Measurements Modifying selection 106 bounds tual menu for the view or the selection table will cause the active view and the selection table to scroll to the active selection There are three ways to modify the bounds i e Begin Time End Time Low Frequency and High Frequency of existing selections Moving selection control points When a selection is active you can modify its selection bounds by manip ulating its selection control points in any view Selection control points can be moved either by dragging with the mouse or using the arrow keys on the keyboard In order to move a control point with the arrow keys you must first activate the control point by clicking on it You can activate dif ferent control points in succession by repeatedly pressing the lt Tab gt key when any control point is active Editing in the selection table You can change the Begin Time End Time Delta Time Low Frequency High Frequency and Delta Frequency values for a selection by editing the value directly in the selection table Any change that you make to one of these fields takes effect when you press lt Enter gt lt Tab gt or any of the arrow keys If you change Delta Time or Delta Frequency field Raven keeps the Start Time and Low Frequency fields constant and adjusts the End Time or High Frequency as necessary Using
100. ctive signal These four measurements are collectively known as the selection bounds Measurement values other than the selection bounds saved in the file are ignored Raven computes the val ues of whatever measurements are currently displayed in the selection table based on the retrieved selection bounds The file from which selection bounds are retrieved need not have been cre ated by saving measurements in Raven Any tab delimited text file can be used for selection retrieval as long as it has the right format see below This means that selection files can be created manually or by an auto mated process such as a signal detection or classification program that is not part of Raven If one or more selections already exist in the active sound window when you retrieve selections from a file Raven will ask you to choose whether to a discard the old selections before retrieving b merge the existing selec tions and the retrieved selections or c cancel the retrieval If you choose Raven 1 2 User s Manual Format of selection Measurements files Chapter 4 Selections and Measurements to merge selections the retrieved selections will be assigned new selection numbers if the saved numbers conflict with existing ones In order for Raven to retrieve selections from a file the first line of the file must be a header row that contains column headings for Begin Time End Time Low Frequency and High Frequency separated fr
101. ctrogram differences among windows in sidelobe rejection result in different amounts of gray fringing above and below black or very dark areas For a given window size different window functions will result in differ ent filter bandwidths see 3 dB Bandwidth on page 80 In terms of a spectrogram this means that the vertical thickness of a horizontal line rep resenting a pure tone will depend on which window function is used Figure 3 5 and Figure 3 6 illustrate the effect of different window functions on spectrogram and spectrogram slice views of the same signal Raven 1 2 User s Manual 77 Chapter 3 Spectrographic Analysis Figure 3 5 Effect of choice of window function on spectrograms The signal is a series of calls from a red breasted nuthatch digitized at 44 1 kHz All three spectrograms have the same window size 512 points 11 6 mS hop size 5 8 mS frame overlap 50 and frequency grid spacing 86 1 Hz FFT size 512 samples 3 dB bandwidths a 141 Hz b 124 Hz c 76 2 Hz 78 Raven 1 2 User s Manual Window size Chapter 3 Spectrographic Analysis a 499 Blackman 50 1 21 dB uz0 000 1 2 3 4 5 b so Hann 50 4 21 dB 20 000 1 2 3 4 5 c 400 Rectangular 50 1 21 dB Hz0 000 14 2 3 4 5 Figure 3 6 Effect of window function on spectrogram slice views These spectrogram slice views were made at the point indicated by the position marker in Figure
102. d array 4 channel aif Spectrogram t Channel 2 Filing ait os er mi i ji Ha ak idni upi 2 aiui r 2 14 gt m Figure 4 3 Channel restricted selections in two channels of a four channel sound Channels 1 and 3 are hidden Selection 1 is defined in channel 2 only selection 2 is defined in channel 4 only selection 3 is defined in both channels When you create a selection in a selected channel the selection will be defined in all selected channels When you create a selection in a non selected channel it will be created in that channel only To change the channels in which a selection is defined after it is initially created use the Selection tab in the side panel as described in Modifying selection channels on page 107 Configuring the selection table 102 Measurement precision and format The number of digits of precision displayed by default for measurement values is determined by measurement precision preferences which you change by editing the Raven preference file For general information on editing the preference file see The Raven preference file in Chapter 6 page 143 for specific information on changing preferences for measure ment precision see Default measurement precision in Chapter 6 page 148 You can change the measurement precision and format for a given mea surement at any time by choosing Format Column from the contextual menu for the measurement
103. d by the Recording Source dia log Figure C 4 To choose which recording source will be used check the Select box for that device To adjust the recording level move the Volume slider control Changes that you make in this dialog box are reflected immediately in the signal reaching Raven You can thus start a recorder running in Raven and then use the Windows audio controls to adjust the recording level See Chapter 2 Signal Acquisition Recording for a discussion of how to set the record level properly ixi Options Help CD Player Line In Microphone Balance Balance Balance iz 4 1 F 4 I j K Volume Volume Volume T Select l Select V Select SigmaTel Audio Figure C 4 The Recording Source controls Controls for different devices may be displayed depending on system configuration Launch the utility program called Audio MIDI Setup located in Applica tions Utilities Audio MIDI Setup is supplied with Mac OS X Click on the Audio Devices tab to display controls for choosing a sound input device and setting the input recording level Figure C 5 For Default Input choose the sound input device that you plan to use with Raven In most cases this will be Built in Audio Under Audio Input left side of window choose the Source to use for input to the audio device In most cases this will be Line In The choices listed for Source correspond to physical input jacks or ports on t
104. d by the lexicographic order of the file names 1 In lexicographic ordering numbers precede letters For example if you were to open two files named abc wav and abl wav as a sequence the data from abl wav would be displayed first followed by the data from abc wav Raven 1 2 User s Manual 119 Chapter 5 Advanced Raven Usage When data from more than one file in a sequence are visible in a view Raven displays dashed green file boundary markers Figure 5 3 4 Sound 1 ChestnutSidedWarbler aif etc m omamne a cd in sja gt Figure 5 3 The files ChestnutSidedWarbler aif and LarkSparrow aif from the Raven Examples folder opened as a file sequence The dashed green vertical line shows the boundary between the two sound files Paged sound windows opening large sounds Configuring a new 120 paged sound window Paged sound windows enable you to open sounds that are too large to fit in the memory available to Raven In a paged sound window Raven loads only a specified amount of the sound called a page into memory at one time The portion of the entire signal that is presently in memory is called the current page A paged sound window includes a page navigation panel that enables you to jump easily to any other part of the signal that s not presently in memory Paged sound windows can be used to display single sound files or file sequences Paged sound windo
105. d in Editing color schemes in Chapter 5 page 129 Raven can display views that have a time axis i e waveforms and spec trograms across multiple lines Figure 1 30 The values shown on the time axis of a multiline view start at the left end of the top line go to the right end of that line and continue on from left to right on subsequent lines like lines of text on a page Raven 1 2 User s Manual 37 Chapter 1 Getting Started Grouping views with multiple lines 38 E Sound 1 BlackCappedVireo aif Figure 1 30 A spectrogram view with three lines Note the continuity of the time axis from one line to the next On the side panel the Layout tab s Lines box shows you how many lines there are for the selected view To change the number of lines select a waveform or spectrogram view change the number in the box and press lt Enter gt By default all waveform and spectrogram views in a sound window are linked to each other in the number of lines displayed You can unlink the number of lines property as described in Unlinking and link ing views on page 20 The scale of the time axis doesn t change when you change the number of lines displayed To rescale the axis so that the view fills the available lines click on the horizontal Zoom to All button at the right end of the horizontal scrollbar In sound windows with two or more views and two or more lines per view you can change th
106. d sound is played during acquisition It is sometimes necessary or useful to acquire sounds from a recording that is being played back either slower or faster than the original recording speed For example ultrasonic signals of bats and dolphins cannot be Raven 1 2 User s Manual 67 Chapter 2 Signal Acquisition Recording properly digitized using most computer sound cards because these cards can only digitize sounds up to 22 kHz half the maximum sampling rate on most sound cards without aliasing One solution is to shift the fre quencies in the recorded input sound down below 22 kHz during acquisi tion by playing the sound back at a reduced speed Input speed adjustment is useful only when acquiring from a 3 recording that can be played back at altered speed If you need to record ultrasonic signals directly into Raven from a live source you need to have a sound card that provides a sampling rate at least twice the highest frequencies in the sig nal For further information about sampling rates see Sam pling rate in Appendix A page 154 When working with signals that are too low in frequency to be audible it may be convenient to play the tape back at a high speed during acquisi tion so that you can hear the signals as they are acquired If you click on the Advanced button at the bottom of the Configure Recorder dialog an additional tab labelled Speed becomes available Fig ure 2 8 The Speed tab le
107. d tone 100 mS long sampled at 22 05 kHz The tone sweeps upward in frequency from 4 to 6 kHz Spectrograms a and c have the same window size but c has finer time grid spacing higher record overlap c and d have the same time grid spacing but d has a shorter record length finer time analy sis resolution a Record length 512 points 23 2 mS 3 dB bandwidth 61 9 Hz Time grid spacing 23 2 mS overlap 0 b Waveform view with duration of tone highlighted c Record length 512 points 23 2 mS 3 dB bandwidth 61 9 Hz Time grid spacing 1 45 mS overlap 93 8 d Record length 64 points 2 9 mS 3 dB bandwidth 448 Hz Time grid spacing 1 45 mS overlap 50 Frequency grid Frequency grid spacing is the difference in Hz between the central analy spacing and DFT sis frequencies of adjacent filters in the filterbank modeled by a STFT and 172 size thus the size of the frequency bins in a spectrogram In an unsmoothed spectrogram this spacing is visible as the height of the individual boxes Figure B 6 Frequency grid spacing depends on the sample rate which is fixed for a given digitized signal and DFT size The relationship is frequency grid spacing sample rate DFT size where frequency grid spacing and sample rate are measured in Hz and DFT size is measured in samples Thus a larger DFT size draws the spec Raven 1 2 User s Manual Spectral smearing and sidelobes
108. do Edit menu 35 rendering data entries in Memory Manager 140 retroactive recording to files 64 Retroactive Recording Offset parameter Configure New Recorder dialog box 64 71 RGB color chooser 133 134 RMS Amplitude measurement 113 S sample frame 57 sample rate conversion during recording 69 70 sample size 53 157 158 Raven 1 2 User s Manual samples internal floating point representation 158 sampling 153 sampling rate 154 156 saturation in HSB color chooser 133 Save Active Selection As File menu 107 Save As dialog box 43 Save Color Scheme Preset dialog box 135 Save Sound Window Preset dialog box 42 scale of a view 14 15 changing 14 default 14 linkage 16 resetting 16 setting 128 zoom in 15 zoom out 15 scheduled recording 70 scroll thumb 10 13 scrollbars 13 paging 123 visibility and window presets 42 scrolling playback 9 10 See also recording a signal selection 31 selection bounds 32 110 111 selection control points 27 active 27 extender point 27 selection files 110 format 111 retrieving 110 selection ID 27 31 selection label 27 selection labels configuration 42 visibility 42 selection number 31 selection spectrum views 73 75 97 creating with linked parameters 128 selection table Activate Next Selection button 105 Activate Previous Selection button 105 Down arrow button 105 Up arrow button 105 selection tables 30 32 33 and paged sound
109. dow presets default 146 sound windows paged 120 spectral smearing 173 175 spectrogram caching Memory Used and 140 spectrogram colormap 36 Spectrogram Parameters View menu 97 spectrogram presets 88 default 145 spectrogram slice view significance of spectrum values 96 time position 95 spectrogram slice views 17 19 20 73 74 95 96 See also spectrogram views creating with linked parameters 128 hidden time axis 19 linkage to spectrogram views 19 20 relationship to spectrogram views 17 time position of 19 spectrogram smoothing 168 169 spectrogram view 5 spectrogram views 73 74 88 90 92 95 brightness 7 88 90 caching of data 140 changing parameters 97 colormap 36 contrast 7 88 90 creating 7 creating with linked parameters 128 linkage to spectrogram slice views 19 20 parameters and window presets 42 relationship to spectrogram slice views 17 significance of color grayscale values 88 smoothing 92 95 speed of calculation 159 time alignment of data 90 92 spectrograms 91 93 94 165 168 176 spectrum averaging 85 87 spectrum source data 90 spectrum time 90 speed correction during signal acquisition 67 Speed tab Configure New Recorder dialog box 68 ss tag in file name templates 59 start time for naming recorded files 60 190 Step Back button 123 Step Forward button 123 step increment 120 123 reconfiguring 123 STFT short time Fourier transform 166 Stop
110. ds in this box tell Raven whether to acquire the signal to memory or to one or more files what input device and device configuration to use and how to display the sound while it s being acquired For now to give you a feel for Raven s capabilities we ll show you how to record sounds to memory without saving them to disk and what you can do with the signal as it s coming in Chapter 2 Signal Acquisition Recording explains in detail what each of the fields in this dialog box do For now just leave all the fields as they are and click OK or press lt Enter gt S Configure New Recorder x Preset Record To Memory ti Input Display Device SigmaTel Audio About Device Configuration Sample Rate 44100 Y Hz Channels v Left _ Right Sample Format 16 bit signed PCM vY Figure 1 33 Raven s Configure New Recorder dialog box The Recorder When you click OK or press lt Enter gt in the Configure New Recorder dia Window log box a new recorder window appears on the Raven desktop Figure 46 1 34 A recorder window looks and behaves like any other Raven sound window except that it has additional controls displayed in the status bar at the bottom of the window Raven 1 2 User s Manual Starting and stopping the real time signal display Displaying real time spectrograms and spectrogram slices Chapter 1 Getting Started gt Not recording
111. e A list file is a plain text file filename extension txt that lists the names of a series of sound files to be opened together as a sound file sequence A list file is created automatically by Raven when you record to a file sequence see Recording to a file sequence in Chapter 2 page 61 You can also create a list file manually in a word processing or text editing pro gram Raven 1 2 User s Manual 117 Chapter 5 Advanced Raven Usage 118 To open a file sequence using a list file choose File gt Open Sound Files or type Ctrl O Windows or Command O Mac OS In the Open Sound Files dialog box that appears Figure 1 1 page 2 Figure 1 2 page 2 choose or type the name of the list file then click OK In the Configure New Sound Window dialog box you can then choose either to open the entire file sequence or to open the sequence in a paged sound window Paged sound windows are discussed in Paged sound windows opening large sounds on page 120 A new sound window will appear displaying all of the audio data from all of the sound files specified in the list file or data from the first page of the sequence in the order that the file names appear in the list file Format of a list file A list file consists of a series of file name entries one per line Each entry can be a simple file name a relative path name or an absolute path name If the entry is a simple file name Raven looks for the file in the same di
112. e Channels pane on the side panel s Layout tab Selected channel numbers are highlighted in yellow in the Channels pane Raven 1 2 Mjo x File Edit View Window Help O BEUL ee eee gt b E Rate 1 0 Z Sound 1 Bird array 4 channel aif 8 RESAS Channel 1 if H Lint vy i hi r nn mil Rpts gil chr hong Es shy Mo AM RS Rp Ce ER AR a es hee Lines 1 Group By Channels SSNS Lil ool O iS S G v Axes v Line Titles v Position Markers v Scrollbars v Selection Control Points v Selection Labels v Selection Table v View Selection Buttons 4 Em x hn Figure 5 8 A multi channel sound window with Channels 1 and 3 selected for editing The view selection buttons for the selected chan nels and their entries in the side panel s Channels list are yellow Correcting sounds acquired at altered speeds It is sometimes necessary or useful to acquire sounds from recordings played at speeds slower or faster than the speed at which they were recorded as discussed in Advanced options acquiring from recordings at altered input speeds in Chapter 2 page 67 Sounds that were acquired with the appropriate speed correction in Raven 1 2 and subsequent ver sions as discussed in that section require no further corrections How ever if you have sound files that were acquired at altered input speeds w
113. e and frequency analysis resolu tion in a spectrogram These two demands are intrinsically incompatible however the record length and filter bandwidth of a STFT are inversely proportional to each other and cannot be varied independently Although a short record length yields a spectrogram with finer time analysis resolu tion it also results in wide bandwidth filters and correspondingly poor frequency analysis resolution Thus a tradeoff exists between how pre cisely a spectrogram can specify the spectral frequency composition of a signal and how precisely it can specify the time at which the signal exhib ited that particular spectrum The relationship between record length and filter bandwidth applies to each of the individual spectra that collectively constitute a spectrogram Figure B 5 illustrates the relationship between record length and filter bandwidth in individual spectra The two spectra of a 2000 Hz pure tone digitized at 22 05 kHz were made with different record lengths and thus different bandwidths Spectrum a with a record length of 1024 points 46 0 mS shows a fairly sharp peak at 2000 Hz because of its relatively narrow bandwidth 35 3 Hz filter spectrum b with a record length of 256 points 11 5 mS corresponding to a wider bandwidth 141 Hz filter has poorer frequency resolution Raven 1 2 User s Manual 167 Appendix B Spectrum Analysis kHz 1 600 1 800 2 000 2 200 2 400 1 600 1 800 F
114. e way the lines and views are grouped in the win dow By default Raven displays all the lines for one view followed by the lines for the next this is called grouping by view Figure 1 31 The alterna tive is to see all the first lines for all views followed by all the second lines for all views and so on this is called grouping by time Figure 1 32 Raven 1 2 User s Manual Chapter 1 Getting Started Sound 2 BlackCappedVireo aif 0 000 ll il OO OOO kU g0 2 4 6 8 10 20 4 Waveform 1 Line 2 0 000 Figure 1 31 A sound window containing two views each with two lines grouped by view All lines of the waveform view are in the top group all lines of the spectrogram view are in the next group Raven 1 2 User s Manual 39 Chapter 1 Getting Started A Sound 2 BlackCappedVireo aif Waveform 1 Line 1 10 Spectiod ig 5 4 ae 5 ti na 0 000 hah Mik kHz 50 20 4 Waveform 1 Line 2 a Figure 1 32 The same two views shown in Figure 1 31 but grouped by time The first lines of both views are in the top group the second lines of both views are in the next group To change the grouping choose View or Time from the pull down menu labeled Group By in the side panel s Layout tab The horizontal separator bar that Raven displays between 3 top level groupings i e between views in View grouping or between lines in Time grouping is wider than the bar used bet
115. eCtion eere go wl bd aa tcl ea Heed de ed Geeta ned 29 Deactivating and clearing selections nanna 0 0 ee 30 The Selection Table 2 2 0 0 eee eee 30 Choosing measurements to display 0 0 0 c eee 32 Annotations eeri Saeed recia PEAS aoe in eens stein beeen ees 33 Saving the selection table to a text file 6 2 0 0 eee eee 33 Editing 4 SOUnNG erste Sun ihe van pub tare yy sees uvae cues Renee E ies 34 Cut Copy Paste and Delete 00 002 e eee 34 Undoing changes rss errar etier einernie tees 35 Filtering and amplifying sounds aaau aaua 35 Color SCHEMES wii sis dss ssania nin wd A AA EY Rew 8 He eNews GR alee ok 36 Spectrogram colormapsS 000 tees 36 Editing color schemeS 0 0 00 eee 37 Multiple line views sios seein Vie Sis wees vetn iad bie sees Aas 8 37 Grouping views with multiple lines 0 00000 38 Working with more than one sound 0 cece cece eee eens 40 Using sound window presets cece cece cece eee cece ence anes 41 Saving and retrieving your WOrk 0 cece e ee cee eens 43 SaVving a SIQNAll ogi win as Ge aga REEE TENES oh end TERA a Sea 43 Saving and opening workspaces 0 000 eae 44 Printing and exporting images cee eee cece cece eee eee 44 Printinge aa a Bee eid el a a Ge aes Ed 44 Exporting images to files 2 0 2 ete 45 Copying images to the clipboard 0 2 0 cee ee 45 Recording a sound
116. en you apply a saved preset the active window is redrawn with the properties specified in the preset and any additional views are calculated as needed You can specify a window preset to apply when you first open a sound file in the Configure New Sound Window dialog box Figure 1 3 page 3 You can change the name of the default window preset by editing the Raven Raven 1 2 User s Manual Chapter 1 Getting Started preferences file as described in Sound window presets in Chapter 6 page 146 If you make changes to the properties of a window to which you ve applied a preset you can save the changes to the current preset by choos ing View gt Window Preset gt Save Preset name affect the appearance of the contents of a window Thus if you apply a window preset spectrogram parameters the measurement list and the color scheme are all set as defined in the specified window preset even if they were previously set to different values by choosing spectrogram measure ment or color scheme presets b Window presets take precedence over other presets that Saving and retrieving your work Saving a signal Raven provides two different ways to save your work When you save a sound file any changes made to the audio data in the active sound window are saved in an audio file When you save a workspace all aspects of Raver s state are saved By saving a workspace first you can quit from Raven and
117. end of the appendix Several approaches can be taken to explaining the fundamentals of digital spectrum analysis The approach taken in this appendix is geared specifi cally to spectrum analysis with Raven thus some of the terms and con cepts used here may not appear in other more general discussions of spectrum analysis such as those listed at the end of the appendix The discussions in this appendix assume a basic understanding of how sound is recorded and represented digitally If you are not already acquainted with concepts such as sampling rate and sample size you should read Appendix A Digital Representation of Sound before pro ceeding Sound consists of traveling waves of alternating compression and rarefac tion in an elastic medium such as air or water generated by some vibrat ing object a sound source Sound pressure is the usually small alternating incremental change in pressure from ambient pressure that results from a sound When no sound is present in a medium i e there is no propagating pressure change we say that sound pressure is zero even though the medium does exert some static ambient pressure The dimensions of pressure are force per unit Raven 1 2 User s Manual 161 Appendix B Spectrum Analysis area The usual unit of sound pressure is the pascal abbreviated Pa one pascal equals one newton per square meter Since the smallest audible sound pressures in air are on the order of 10 Pa
118. epresented as 13 When recording to a file or file sequence if a file to be created has the same name as a file that already exists in a given directory Raven by default creates a new subdirectory and puts the new file there in order to avoid overwriting the old file The new subdirectory is named Collisions date time where date and time identify the time when the directory was created using the format lt yyyy gt lt 11 gt lt dd gt lt hh gt lt mm gt lt ss gt see Table 2 1 on page 59 When this happens Raven displays a message showing the name of the file and the directory into which it was placed Raven 1 2 User s Manual Chapter 2 Signal Acquisition Recording Alternatively you can configure Raven to overwrite existing files when file names collide by editing an entry in the Raven preference file as described in Overwrite behavior for recorders in Chapter 6 page 151 Recording to a file sequence If you choose Record to File Sequence the File Names tab appears Fig ure 2 5 The File Names tab contains the same fields as shown on the File Name tab used for single file recording see File naming on page 57 with the addition of a List File field S Configure New Recorder J xj Preset Record To File Sequence Y Input Display File Format File Names Directory Browse List File Sound Files Example Start Time Now Other yor
119. er 2 Signal Acquisition Recording x 2 Configure Recorder 1 x Preset Record To Memory x Input Speed Rate Conversion Display Schedule The input sound is At normal speed Slowed down by a factor of Sped up by a factor of Figure 2 8 The Speed tab of the Configure New Recorder dialog box This tab is visible only after you click the Advanced button which is then replaced by the Simple button Advanced options sample rate conversion during recording Why decimation is useful Raven can decimate a signal as it is being acquired Decimation is a way of reducing the sampling rate of a signal by retaining every Nth sample and discarding all others Raven automatically applies a low pass filter to a signal before decimating it in order to prevent aliasing in the decimated signal For low frequency sounds the lowest sampling rate available with a par ticular device may be many times higher than needed to represent the sig nal accurately This can lead to digitized signals that are much larger than necessary which require more storage and longer processing times Deci mation during signal acquisition is a way of reducing the sampling rate to a rate that is more appropriate for the signal Appendix A Digital Repre sentation of Sound discusses choice of sampling rate further For example most of the sounds made by blue whales or elephants are at frequencies below 100 Hz
120. er can be retrieved by opening the file s that were saved during the acquisition The update rate determines how many times per second views in the recorder window are redrawn during signal acquisition The default rate is 10 Hz There is a trade off between the perceived smoothness of the scrolling real time display and Raven s responsiveness to user interaction If the update rate is too low scrolling views move in visibly discrete steps resulting in a jittery display If the update rate is too high Raven will be slow to respond to user actions such as mouse clicks or keyboard com mands In practice the best rate will depend on the size of the recorder window the number and type of views it contains and the speed of the Raven 1 2 User s Manual Latency Window preset Chapter 2 Signal Acquisition Recording computer The default update rate of 10 Hz provides a good balance between display smoothness and performance on most computers You may need to experiment to determine what update rate provides the best performance on your computer See Reconfiguring an existing recorder on page 67 to learn how to change the update rate once a recorder is run ning The Latency value on the Display tab specifies the difference for a running recorder between the current time and the active view s time axis position by default the right hand edge of the window Specifying a display latency greater than zero introduces a delay i
121. er the selected frequency band over just the selected time interval choose Edit gt Filter gt Around Active Selection or Edit gt Filter gt Out Active Selection To filter the selected frequency band over the entire length of the sound choose Edit gt Filter gt Around All or Edit gt Filter gt Out All If there is no active selection the Edit gt Filter menu is not available Amplifying To amplify all or part of a sound choose Edit gt Amplify The Amplify Sound dialog box that appears Figure 5 11 lets you choose whether to amplify the entire sound or just the active selection You can also choose between two methods of amplification you can either specify a factor by which Raven will multiply each sample in the sound or you can specify that Raven should multiply the entire sound or the active selection by whatever factor necessary to make the RMS amplitude of the active selec tion equal to a specified value greater than 0 and less than 1 Amplifying by 0 will silence the b To reduce the amplitude of a sound amplify by a factor chosen portion of a sound S Amplify Sound x Portion Entire Sound Active Selection Method Multiply by factor O Make RMS amplitude of active selection Cancel ll Figure 5 11 The Amplify Sound dialog Editing color schemes Raven provides four predefined color schemes which differ only in their spectrogram color maps as desc
122. erest is at the time position marker The sound stops playing while you drag the scroll thumb and resumes imme diately at the new time position when you release the scroll thumb You can speed up or slow down the playback rate of the signal By default the playback rate is set at 1 0 or the same as the recording rate Slowing down the rate makes the sound lower in pitch and slower speeding it up makes it higher in pitch and faster Try it now type a number greater than 1 in the rate box to speed up or a decimal number between 0 and 1 to slow down press lt Enter gt and then play the sound again Changing the position and scale of a view zooming 10 Position of aview Position markers Each view that Raven displays has a horizontal and a vertical position asso ciated with it shown by a magenta line known as a position marker You have already seen how the time position marker in a waveform view indi Raven 1 2 User s Manual Chapter 1 Getting Started cates the current time during scrolling play Position markers and scroll ing playback on page 9 When we speak of the horizontal position marker we mean the line that marks the horizontal position which is a vertical line You can move the horizontal or vertical position marker of a view relative to the window by grabbing it with the mouse and dragging it To move a particular point in the data shown in a view to the horizontal or vertical cente
123. ers We recommend that you read this chapter at the computer and try the examples as they re dis cussed We assume you know how to browse for files on your computer and have installed Raven as discussed in the Raven README file In this chapter you ll learn how to e open an existing sound file using Raven e display waveform spectrogram and spectrogram slice views of a sound e play all or part of a sound file e hide show and zoom views of a signal e edit a recorded sound e save your changes e make and save measurements of a signal e record new signals Opening a sound file Launch Raven by double clicking on its icon Depending on how you installed Raven there may be an icon for it on your desktop in your Start menu Windows in your dock Mac OS or you may have to open the Raven folder to find it The Raven window appears on your screen To open a sound file choose File gt Open Sound Files or type lt Ctrl O gt Windows or lt Command O gt Mac OS You ll see Raven s Open Sound Files dialog box Figure 1 1 Figure 1 2 Raven 1 2 User s Manual 1 Chapter 1 Getting Started CanyonWren wav Oct 21 2002 12 03 PM 808 Open Sound Files Examples H Name Date Modified amp 2000Hz aif Mar 17 2003 10 33 AM AfricanForestElephants aif Mar 19 2003 12 00 PM BeardedSeal aif Aug 23 2002 10 00 AM Bird array 4 channel aif Mar 17 2003 2 39 PM BlackCappedVireo aif Oct 7 2002 3 16 PM
124. et is applied to a sound window the 3 color scheme s specified in the window preset take prece dence over the default color scheme preset See Using sound window presets on page 41 Workspace files are discussed in Saving and opening workspaces in Chapter 1 page 44 You can specify a default workspace for Raven to open each time the pro gram is launched by uncommenting and editing the following entry in the preference file raven workspace defaultWorkspace Workspaces Default wsp The notation means that the remainder of the specified pathname is within the Raven program directory If you want to use a default work space that is located elsewhere you must specify a complete path as in raven workspace defaultWorkspace C MyRavenStuff MyDefault wsp A default workspace is useful for changing the initial appearance of the Raven window For example the main Raven window is by default ini tially 750 pixels wide and 550 pixels tall If you want Raven to always start with a window that fills the entire screen you can launch Raven expand the window to full screen and then save the workspace Then edit the preference file to specify that workspace as the default Thereafter Raven will start with a full screen window In addition to window size the work Raven 1 2 User s Manual 147 Chapter 6 Preferences Default directories space will save information on the state of the side panel vi
125. g Started Saving and opening When you save a workspace all information about Raven s state is saved workspaces including what signals are open the size and placement of their windows what views exist for each sound window what if any selection table file is open for each sound window and linkages among views within and between sound windows To save the workspace choose File gt Save Workspace As Raven workspace files can be saved anywhere and must have a filename extension of wsp To open a workspace file choose File gt Open Workspace If you have any sound windows open Raven will warn you that they will be lost when the workspace file opens and ask if you want to proceed If there are signals open with unsaved changes Raven gives you the opportunity to save them before opening the workspace file Once the saved work space opens Raven is completely restored to its state at the time the work space was saved When you save a workspace file Raven saves the name and location of each open sound file and its corresponding selec tion table file this information is used to re open the original sound files and recreate selections when the workspace file is opened later If you move rename or delete a sound file or a selection table file that is referenced in a workspace file Raven will not be able to find that file when the workspace is opened If you copy or move a workspace file to a different computer you m
126. g enables you to start recording to a file or file sequence beginning at a time in the recording buffer before the moment that you clicked the Record to Disk button Retroactive recording is discussed further in Retroactive recording to files on page 64 Problems with recording Device unavailable Unsupported audio format If when you click on the Start Recording button in a recorder window Raven displays a message indicating that the audio device is unavailable check to make sure that there is not another recorder running within Raven Only one recorder at a time can be running Another possible rea son for this condition is that the audio input device has been allocated by another application If there is another audio application running you may need to quit from it in order to record in Raven Some audio CD player programs allocate the audio device for their exclusive use Such applications cannot be used to play CDs for input into Raven If you have this problem try using a different program for playing CDs While using some audio CD player programs attempts to record with Raven may result in an error message stating that the specified audio for mat is not supported In most cases this message is itself erroneous i e the audio format is supported and the problem can be rectified by using a different audio CD player program Raven 1 2 User s Manual 71 Chapter 2 Signal Acquisition Recording 72 Raven
127. ghtness and contrast controls If your spectrogram looks too dark or light or if it s hard to pick the signal out of the background move the brightness and contrast sliders to achieve the desired appearance of the spectrogram The brightness control adjusts the overall darkness of the spectrogram for a grayscale spectrogram the default sliding the control to the right lightens the display The contrast control adjusts the number of different color by default grayscale values that are shown in the spectrogram In a grayscale spec trogram moving the contrast slider all the way to the right makes the dis play black and white all values below some threshold are assigned to Raven 1 2 User s Manual 7 Chapter 1 Getting Started Moving and resizing a sound window The side panel Playing a sound white and the rest become black In this case the threshold between black and white is determined by the brightness control With the contrast con trol all the way to the left Raven displays up to 200 shades of gray The box next to each control tells you what percent contrast or brightness you ve set If you prefer you can type a percentage number into a box instead of moving the slider See Brightness and contrast in Chapter 3 page 88 for a more detailed explanation of how these controls work The sound window s title bar has controls for moving resizing and clos ing it Figure 1 4 Figure 1 5 To move the window
128. glewood Cliffs NJ xiv 585 p A classic reference written principally for engineers Raven 1 2 User s Manual 177 Appendix B Spectrum Analysis Rabiner L R and Gold B 1975 Theory and Application of Digital Signal Processing Prentice Hall Englewood Cliffs NJ xv 762 p Another classic engineering reference Yost W A and Nielsen D W 1985 Fundamentals of Hearing An Intro duction 2d ed Holt Rinehart and Winston New York x 269 p A good general text on human hearing that includes some discus sion of the elementary physics of sound and an appendix that introduces basic concepts of Fourier analysis 178 Raven 1 2 User s Manual AppendixC Configuring Audio Input About this appendix This Appendix explains how to use controls provided by your operating system to select and adjust the audio device from which Raven gets its input when acquiring new signals Windows 98 2000 and XP Depending on which version of the Windows operating system you re using the icons and windows you see may appear slightly different from those shown here However the audio input controls function the same way in all versions of Windows To access the Windows audio input and output controls double click on the speaker icon that is displayed in the icon tray in the Windows task bar Figure C 1 AGS 9 03AM Audio controls Figure C 1 The Windows icon tray Double click on the speaker icon to display the Wind
129. gt Win dows or lt Command N gt Mac OS The clipboard can hold only one item at a time whenever you Cut or Copy the data that go into the clipboard replace what was there before You can delete the data in the active selection either by choosing Edit gt Delete or by pressing lt Ctrl backspace gt Windows or lt Command back space gt Mac OS Cut Copy Paste and Delete operations apply only to the time dimension of a sound window If you select a region for one of these operations in a spectrogram the operation applies across all frequencies in the signal for the duration of the selection irrespective of the frequency limits of the selection Figure 1 28 shows the lark sparrow song filename LarkSparrow aif from the Raven Examples directory before and after a series of editing operations As an exercise try rearranging parts of this signal to make it look like the edited version in the figure Raven 1 2 User s Manual Undoing changes Filtering and amplifying sounds Chapter 1 Getting Started My ab i in 0 000 kHz 50 1 2 3 4 5 Figure 1 28 The lark sparrow song from the Raven Examples folder a before and b after a series of editing operations When you modify a sound Raven adds an asterisk to the beginning of the title of the sound window to show that you ve edited the sound If the file is restricted to read only access the title bar tells you that too in
130. h spectrum in a spectrogram Hence the color value is proportional to the power expressed in decibels relative to an arbitrary reference power The numeric values for relative power level associated with each point are displayed in decibels dB in the mouse measurement field at the bottom of the signal window These decibel measurements are relative to an arbi trary spectrogram bin reference value of 1 surements In other words the dB values given by Raven do not represent absolute sound levels Raven s amplitude mea surements can be used to obtain accurate relative measure ments within signals y Raven 1 2 does not display calibrated sound amplitude mea The section on Spectrogram brightness and contrast in Chapter 1 page 7 provides a basic introduction to the operation of the spectrogram Raven 1 2 User s Manual Chapter 3 Spectrographic Analysis brightness and contrast controls This section provides a more detailed explanation of how these controls work The information in this section is not needed to use the controls effectively it is provided for those who are interested in a quantitative explanation of how these controls affect the spectrogram image Each spectrogram has an associated floor value and ceiling value Powers that are less than or equal to the floor value are displayed as the floor color powers that are greater than or equal to the ceiling value are displayed as the ceiling color
131. h that the num ber of spectra in the visible time span is much greater than the number of pixels in the time dimension of the sound window then many spectra will not be displayed at all Some acoustic events that span only a few spectra may not be visible unless you zoom in to display a finer time scale because the only spectra in which they appear fall between the pixels shown in the display By setting the Averaging field to a value greater than one spectrum you can make visible short duration events that would oth erwise be lost between pixels Second spectrum averaging smooths back ground noise which can result in a higher signal to noise ratio in the spectrogram image Figure 3 11 At finer time scales i e greater magni fication in the time dimension however spectrum averaging tends to blur signals Figure 3 11 You can specify the amount of data to average in units of seconds or milli seconds rather than spectra using the units drop down menu Raven 1 2 User s Manual Apply and Auto apply Chapter 3 Spectrographic Analysis Avefagi WAN Hz g 6 8 165 10 12 EN N mo WM ue tft il 0 000 ial 6 8 165 10 12 c s4Averaging 1 Y AE fed Flia A pil 4 re i i A Pa 7 vA Aw A 5 0 000 kHz 5 f 8 165 g 10 kHz 8 7 8 165 9 10 Figure 3 11 Spectrum averaging can yield clearer spectrograms when the interval in view is long compared to the number of spectra in view All four s
132. h zoom operations are cen tered Third the position of a view in a particular dimension e g time or frequency may be used to link that view to any other view that shares that dimension see Unlinking and linking views on page 20 And fourth during scrolling playback the time position moves through the data though the position location stays fixed see below and can be used to control where playback starts see Position markers and scrolling play back on page 9 12 Raven 1 2 User s Manual Chapter 1 Getting Started Position vs position location The position of a signal identifies a point in the data along a particular axis such as time or frequency In contrast the position location is the point in a particular view s panel where the position marker is displayed i e from left to right or top to bottom For example when you drag a time position marker you change both the position location relative to the window and the position relative to the data since the data do not move with the marker When you click the Center Position button for an axis the posi tion marker jumps to the corresponding horizontal or vertical center of the view panel and the data move with it i e the position location changes but the position relative to the data does not Scrollbars The horizontal and vertical scrollbars in a Raven sound window always refer to the active view The length of the horizontal scrollb
133. hat you enter by typing in a field e g Red Green or Blue values in the RGB color chooser the change is applied when you complete an entry by pressing the lt Enter gt or lt Tab gt key or by clicking in another field If the Auto apply checkbox is unchecked changes that you make in the Color Scheme Editor are not applied until you click the Apply or OK but ton Clicking the OK button applies the changes and closes the dialog Clicking the Apply button applies the changes but leaves the dialog open Clicking the Close button closes the dialog without applying changes If you click the Reset button before applying changes the color and opac ity settings revert to their previous values If Auto apply is checked the Reset button will not restore the color and opacity settings in effect before you made changes The Preset Manager Table 5 2 lists all of the types of presets available in Raven You create pre sets by choosing Preset gt Save As in any dialog box that supports pre sets Raven 1 2 User s Manual 135 Chapter 5 Advanced Raven Usage Table 5 2 Types of presets available in Raven Audio File Format Audio File Names Audio Recorder Audio Recorder Display Audio Recorder Input Audio Recorder Schedule Color Scheme Measurement List Sample Rate Conversion Selection Labels Sound Window Spectrogram Parameters You can use the Pre
134. he Configure Selection Labels dialog box Figure 4 8 To remove an item from selection labels highlight its name in the list of Displayed Items and click the right pointing arrow button You can also enter a string of text that will appear as a separator between items in the selection labels the default separator is a single space character Raven 1 2 User s Manual 109 Chapter 4 Selections and Measurements S Configure Selection Labels x Preset Displayed Items Available Items Selection ID Begin Time End Time l Low Freg High Freq rc Item separator Location Top Bottom Font size v Auto apply ox Apply Reset Close Figure 4 8 The Configure Selection Labels dialog box i You can specify colors for active and inactive selection labels via the color scheme editor View gt Color Scheme gt Edit as described in Editing color schemes in Chapter 5 page 129 Saving and retrieving selections 110 The section Saving the selection table to a text file in Chapter 1 page 33 describes how to save data from a selection table into a tab delimited text file Once such a selection file has been saved you can retrieve the selec tions by choosing File gt Open Selections When Raven retrieves selections from a file it uses the Begin Time End Time Low Frequency and High Frequency values read from the file to create new selections in the a
135. he computer or external audio device To adjust the recording level move the Volume slider control Changes that you make to the recording level in Audio MIDI Setup are reflected immediately in the signal reaching Raven You can thus start a recorder running in Raven and then use the Audio MIDI Setup controls to Raven 1 2 User s Manual 181 Appendix C Configuring Audio Input adjust the recording level See Chapter 2 Signal Acquisition Recording for a discussion of how to set the record level properly Do not make changes to the audio input format sample rate 3 number of channels and sample size in Audio MIDI Setup while Raven is running Doing so may result in corrupted recordings in Raven Def Built in Audio System O i Built in Audio Built in Audio Built in Audio z ERAT Internal speakers 44100 0Hz 2ch 16bit Figure C 5 The Audio Devices screen in the Audio MIDI Setup pro gram 182 Raven 1 2 User s Manual INDEX A acquiring a signal 47 See recording a signal acquisition See also recording a signal Activate Selection selection contextual menu 28 Activate Selection N selection contextual menu 105 active selection 28 active view 7 13 active window 40 aif filename extension 43 AIFF file format 43 56 aliasing 69 154 156 Amplify Sound dialog box 129 amplifying 129 analog to digital conversion 153 analysis frequency 166 analysis resolution 169 17
136. he view is immediately redrawn if necessary so that its image has the correct scale position or other linkable property If a linkage group contains only a single view and you drag that view to a different linkage group the original now empty group disappears Raven 1 2 User s Manual Creating a new linkage group Other linkable properties Chapter 1 Getting Started To create a new linkage group drag a view icon onto the icon labeled New in the Linkage tab A new linkage group will appear containing the view that you moved In addition to its position and scale for each of its dimensions every view has three other properties by which it can be linked to other views e Color Scheme Color schemes include color specifications for most of the graphical elements shown in a view e g axes backgrounds selec tion boundaries as discussed in Color schemes on page 36 Adjusting brightness and contrast settings for a spectrogram adjusts the settings for all spectrograms linked to it by Color Scheme By default all views of a signal are linked to each other by Color Scheme e Channel Visibilities In multi channel signals see Working with multi channel sounds in Chapter 5 page 124 hiding or showing par ticular channels of a view will also hide or show those channels in other views that are linked by Channel Visibility e Number of Lines Changing the number of lines displayed for a view see Multiple li
137. heme Editor dialog The Swatches color chooser is displayed by default when the Color Scheme Editor is first opened To change the color of a particular element of a color scheme choose the name of that element from the Color drop down menu and then set its color using one of the three color choosers that appear on the tabs in the middle of the dialog box Raven s color choosers provide three different ways of specifying colors as described below For all color choosers a sample of the color chosen is shown in the Preview panel in the lower third of the dialog box Swatches color chooser When you first open the Color Scheme Editor dialog box the Swatches tab is displayed by default Figure 5 13 To change the color of the selected color scheme element click on one of the small color swatches in the rectangular color palette Each time you click on a swatch a swatch of that color is added to the small Recent palette to the right of the main pal ette You can choose any color that you have used recently either from the Recent palette or from the main color palette Raven 1 2 User s Manual Chapter 5 Advanced Raven Usage HSB color chooser The HSB color chooser Figure 5 14 allows you to choose colors for each element in a color scheme by specifying the element s hue saturation and brightness You can set the hue saturation and brightness either by typing numerical values into the H S and B text fields or by using the
138. hile acquisition is stopped 2020 0520e00es 67 Reconfiguring while recording 0c ccc eee 67 Multiple recorder windows 02 000 cece eect 67 Advanced options acquiring from recordings at altered input speeds 67 Advanced options sample rate conversion during recording 69 Why decimation is useful 0 0 0 0 00 eee 69 Decimation Factor reses resi ee ee eed ee Pee ee ee 70 Advanced options scheduled recording cece cece eee eee 70 Retroactive Recording Offset 0 0 0 cee 71 Problems with recordine osseo syresh oeyoo ela tae UA se ay 71 Devicecunavailable wth cern gah be eee IEAA pip ee ate sada Ra aaah 71 Unsupported audio format 00 0c eee 71 Spectrographic Analysis 22 0 hws SiGe don eae ee 73 About this chaptetiii scispitoros caged soteecss peered shores bea bedss 73 About spectrographic views 00 ccc eee e ee ee eee ee eaes 73 Raven 1 2 User s Manual iii Hop Size Chapter 4 How the spectrographic views are related 2 2 20000 eee eee 74 Configuring spectrographic views sssssssssssssssssssoessssses 75 Window Ype caisean i ee ee ee ee eed EE TEERAA Seed 76 WIndOW SIZO ar in a A EE E EAE E RA as TERA A 79 Window Size slider control 0 0 00 ee 80 Beta Kaiser window only 00 000 cece eee eee 80 3 dB Bandwidth iter ieie a ania aaa a a tees 80 Choosing the window Size 1 0 dra e aE E NPE EG a CE
139. ick on Open in separate windows After choosing either to open each file in its entirety in a single window or in a paged sound window see Paged sound windows opening large sounds on page 120 click OK Each of the chosen files will open in a sep arate window using the window preset that was specified in the dialog 116 Raven 1 2 User s Manual Chapter 5 Advanced Raven Usage S Configure New Sound Window x Window Speed Preset Default x Paging Open entire sound Page sound Multiple Files Open as file sequence in one window Open in separate windows Figure 5 2 The Configure New Sound Window dialog for opening mul tiple files Opening file sequences Using a list file Raven allows you to open multiple sound files as a file sequence provided that the files have the same file format e g AIFF or WAVE sample rate and number of channels When files are opened as a sequence the audio data in the files are concatenated into a single sound signal that opens in one window A sound window containing data from a file sequence looks and behaves the same as a single file sound window except that there is no file name displayed in the title bar Figure 5 3 and Cut Delete and Paste operations are prohibited You can open a sound file sequence either by giving Raven the name of a list file or by manually choosing a set of files to be opened as a sequenc
140. iew The vertical axis of each bar represents the frequency axis of the spectrum The color of the bar varies from bottom to top with the color at a particular frequency i e height along the bar representing relative power or intensity at that frequency for the corresponding record In a spectrogram slice Raven displays only one spectrum at a time Figure 3 2 lower view The choice of which spectrum is displayed at any moment depends on the time position of the spectrogram slice view as Raven 1 2 User s Manual Chapter 3 Spectrographic Analysis described later in this chapter see Time position of a spectrogram slice view on page 95 Spectrogram 20 4 20 555 Spectrogram Slice kHz0 000 0400 0 600 0 800 1 000 1 200 1 400 Figure 3 2 Relationship between spectrogram and spectrogram slice views The spectrogram shown here is a close up of about 1 second from Figure 3 1 encompassing 17 individual spectra Spectrogram smoothing has been turned off to reveal the individual spectra in the spectrogram The highlighted selection identifies the one spectrum that appears in the spectrogram slice view The time position of the spectro gram slice view is indicated by the time position marker in the spectro gram at 20 555 sec In a selection spectrum view Raven displays an average spectrum based on a series of short spectra computed over the time interval of the active selection Figure 3 1 bottom view
141. igure B 5 Relationship between record length and 3 dB bandwidth Each view is of a single spectrum of a 2000 Hz tone digitized at 22 05 kHz In both spectra window function Blackman The highlighted band in each spectrum shows the 3 dB bandwidth a Window size 1024 points 46 0 mS 3 dB bandwidth 35 3 Hz b Window size 256 points 11 5 mS 3 dB bandwidth 141 Hz Making spectrograms A spectrogram produced by Raven is a two dimensional grid of discrete data points on a plane in which the axes are time and frequency Ordi narily this grid is not apparent because by default Raven smooths the spectrogram display interpolating color values for pixels that are between the gridpoints where values were calculated by the STFT algorithm If you turn off spectrogram smoothing and stretch the time and frequency scales adequately the discrete nature of the spectrogram becomes evident Fig ure B 6 In a spectrogram displayed with smoothing turned off the color of each box represents an estimate of the logarithm of the relative sound power in decibels in a particular frequency band over a particular time interval The center point of the box is at the center of the corresponding frequency band and time interval 168 Raven 1 2 User s Manual Analysis resolution and the time frequency uncertainty principle Appendix B Spectrum Analysis kHz Figure B 6 Same spectrogram as in Figure B 4 with smoothing turned off The
142. ing error inherent in the acquisition process Figure A 4 which results in quantization noise in the digitized signal The more bits used for each sample the less quantization noise is contained in the digitized signal If you listen to a signal digitized with 8 bit samples using high quality headphones you can hear the quan tization noise as a low amplitude broadband hiss throughout the record ing Signals digitized with 16 bit samples typically have no detectable hiss The ratio between the value of the highest amplitude sample that can be represented with a given sample size and the lowest non zero amplitude is called the dynamic range of the signal and is usually expressed in deci bels dB The dynamic range corresponds to the ratio in amplitude between the loudest sound that can be recorded and the quantization noise The dynamic range of a digitized sound is 6 dB bit 1 The dynamic range of a signal in decibels is equal to 20 log Ajqy A min where Ajay and Anin are the maximum and minimum amplitude values in the signal For a digitized signal Amax Amin 2 where n is the number of bits per sample Since log 2 0 3n the dynamic range of a signal is 6 dB bit Raven 1 2 User s Manual 157 Appendix A Digital Representation of Sound Specifying sample sizes when acquiring and saving signals Figure A 4 Digitizing error with a hypothetical 2 bit sample size 2 bit samples can represent only four different ampl
143. ion the beginning and end of the bars representing the tones are fuzzy and poorly aligned with fea tures of the waveform compare for example the beginning time of the first pulse in the waveform with the corresponding bar in the spectro gram However this spectrogram has much better frequency resolution than spectrogram a the bar representing each tone is only about 100 Hz in thickness Figure B 7 Effect of record length and filter bandwidth on time and fre quency resolution The signal consists of a sequence of four tones with frequencies of 1 2 3 and 4 kHz at a sampling rate of 22 05 kHz Each tone is 20 mS in duration The interval between tones is 10 mS Both spectrograms have the same time grid spacing 1 45 mS and window function Hann The selection boundaries show the start and end of the second tone a Wide band spectrogram record length 64 points 2 90 mS 3 dB bandwidth 496 Hz b Waveform showing timing of the tones c Narrow band spectrogram record length 512 points 23 2 mS 3 dB bandwidth 61 9 Hz The waveform between the spectrograms shows the timing of the pulses 170 Raven 1 2 User s Manual Time grid spacing and window overlap Appendix B Spectrum Analysis What is the best window size to choose The answer depends on how rapidly the signal s frequency spectrum changes and on what type of information is most important to show in the spectrogram given
144. ions and Measurements Creating renaming and deleting annotation columns Entering annotations 100 To create and name a new annotation column choose Add Annotation Col umn from the selection table s contextual menu Enter a name for the new annotation column in the dialog box that appears and click OK To rename an existing annotation column choose Rename Column from the contextual menu for that column enter a new name for the column and click OK To delete an annotation column from the selection table choose Delete Column from the column s contextual menu the annotation values will be deleted and cannot be retrieved Note that this is different from deleting a column containing one of Raven s built in measurements which will be recom puted automatically if you later add the column again y If you delete an annotation column that contains annotations There are three ways to enter annotation values for selections Entering annotations when committing selections When you commit a new selection see Committed vs uncommitted selections in Chapter 1 page 28 Raven by default displays the Anno tate Selection dialog box Figure 4 2 which lets you enter values for all annotation columns that are currently defined If you do not want Raven to display this dialog each time you commit a selection uncheck the box labelled Show this dialog whenever a selection is committed If you check the box
145. ist file which can be used to open the file sequence as a single continuous signal You create a recorder by specifying a set of configuration parameters in the Configure New Recorder dialog box Figure 2 1 which is invoked by clicking on the Record button on the Raven toolbar identified by the microphone icon left or by choosing File gt New Recorder 099 Configure New Recorder Preset Record To Memory E input Display Device Built in audio controller P About p Device Configuration Sample Rate 44100 4 Hz Channels M Left Right Sample Format 16 bit signed PCM Advanced ox gt Cancel Figure 2 1 The Input tab of the Configure New Recorder dialog box You use the Record To drop down list in this dialog to choose whether to record to Memory a File or a File Sequence Depending on which record ing destination you choose different tabs appear in the dialog box The following sections discuss the configuration options on each tab 52 Device The Input tab Figure 2 1 allows you to choose and configure an audio input device The Input tab is displayed for all three recording modes Click on the Device drop down list to see a list of all available audio input devices By default the operating system s default audio input device is selected The name that is shown for this device will be the name of the Raven 1 2 User s Manual Sample Rate Ch
146. ith older versions of Raven or with another program that did not correct for the altered input speed you can correct the speed when opening the file The Speed tab in the Configure New Sound Window dialog box Fig ure 5 9 allows you to specify the factor by which the sound was slowed down or sped up relative to normal speed when it was acquired The 126 Raven 1 2 User s Manual Chapter 5 Advanced Raven Usage Configure New Sound Window dialog box is displayed after you choose one or more files to open in the Open Sound Files dialog box S Configure New Sound Window x Window Speed The stored sound is At normal speed Slowed down by a factor of O Sped up by a factor of Figure 5 9 The Speed tab in the Configure New Sound Window dialog box If you provide the appropriate speed correction factor when opening the file then Raven will display time and frequency axes of views and mea surements so that they refer to the original sound at normal speed appropriate speed correction factor behave in Raven as if they had been acquired at normal speed Thus to hear sounds that were originally above or below the human hear ing range you will need to specify an appropriately low or high speed for playback as described in Playback rate in Chapter 1 page 10 b Sounds that are acquired at an altered speed using the Raven corrects a file s speed by altering its sample r
147. ith window size of 512 you set DFT Size to 1024 instead of 512 then Raven will change DFT Size to maintain this relationship as you adjust window size When the DFT Size padlock button is locked the DFT size hence fre quency grid resolution is fixed and will not change when the window size changes Because the window size cannot exceed the DFT Size the 3 maximum value you can specify for Window Size either by typing a value or by moving the slider control is limited to the DFT Size value when DFT Size is locked The Averaging field allows you to specify the number of individual spec tra over which Raven should average the power values to obtain the val 1 The parameter that Raven calls DFT Size is sometimes called FFT size in other programs FFT stands for fast Fourier transform which is a particular algorithm used to compute the discrete Fourier transform or DFT Size is a characteristic of a particular DFT not of the FFT algorithm used to compute it Raven 1 2 User s Manual 85 Chapter 3 Spectrographic Analysis 86 ues in each cell of the spectrogram In most situations Averaging should be left at its default value of one spectrum Higher Averaging values may provide more satisfactory spectrogram images when more than a few seconds of a signal are displayed There are two reasons why averaged spectrograms may be preferable at certain time scales First if the time scale of a spectrogram view is suc
148. itude levels The blue sinusoidal curve represents the continuous analog waveform being sampled At each sample time vertical lines the actual amplitude lev els are rounded to the nearest value that can be represented by a 2 bit sample horizontal lines The amplitude values stored for most sam ples dots are slightly different from the true amplitude level of the sig nal at the time the sample was taken Raven lets you specify the sample size for a signal when you first acquire it and again when you save the signal to a file The set of sample sizes that are available during acquisition is determined by the sound input plug in that you select sound acquisition is discussed in Chapter 2 Signal Acquisition Recording While Raven is actually working with a signal samples are always represented by 32 bit floating point values When you save a signal with a sample size other than the sample size that the signal had when it was acquired or opened Raven scales the values to the sam ple size that you select when you specify the format of the file saving files is discussed in Chapter 1 Getting Started with Raven For example if you open a file containing 8 bit samples and then save the signal with 16 bit samples each sample value will be multiplied by 2 This scaling ensures that a full scale value in the original signal is still a full scale value in the saved signal even if the sample size differ with a larger samp
149. l button repeatedly the scale will eventually be stretched to the point where Raven displays the indi vidual samples in the waveform as dots Figure 1 12 Raven 1 2 User s Manual 15 Chapter 1 Getting Started Zoom to selection Zoom to entire axis 16 10 5 0 000 5 10 kU S 0 93 0 93 0 93 0 93 0 93 0 93 Figure 1 12 A waveform view with the horizontal axis zoomed in enough to display individual sample points This signal was acquired with a sample rate of 44100 Hz Notice that both the waveform and spectrogram views zoomed even though only one of them is the active view That s because the time scales as well as the time positions of the views are linked so whatever changes you make to the time scale of one are made to the time scale of the other automatically Linkage of views is discussed in the section Unlinking and linking views on page 20 To zoom vertically in the spectrogram activate that view and drag the vertical position marker to the point where you want to center the zoom Click the or button at the bottom of the vertical axis to increase or decrease magnification around the vertical position marker Notice that changing the vertical position or scale of the spectrogram has no effect on the waveform The vertical dimensions of the views are differ ent amplitude in the waveform frequency in the spectrogram so the vertical scales of the views cannot be linked
150. l broadband noise the effect of aliasing is to increase the noise in the digitized signal How ever if the spectrum of the analog signal contains any peaks above the Nyquist frequency the spectrum of the digitized signal will contain spuri ous peaks below the Nyquist frequency as a result of aliasing In spectro grams aliasing is recognizable by the appearance of one or more inverted replicates of the real signal offset in frequency from the original Figure A 3 Raven 1 2 User s Manual 155 Appendix A Digital Representation of Sound 156 Figure A 3 Appearance of aliasing in spectrogram views a Spectro gram of a bearded seal song signal digitized at 11025 Hz All of the energy in the signal is below the Nyquist frequency 5512 5 Hz only the lowest 2300 Hz is shown The red line is at 1103 Hz one fifth of the Nyquist frequency b The same signal sampled at 2205 Hz one fifth of the original rate Nyquist frequency 1102 5 Hz without an anti alias ing filter The frequency downsweep in the first ten seconds of the orig inal signal appears in inverted form in this undersampled signal due to aliasing c The same signal as in b but this time passed through a low pass anti aliasing filter with a cutoff of 1100 Hz before being digi tized The downsweep in the first ten seconds of the original signal which exceeds the Nyquist frequency does not appear because it was blocked by the filter The usual way t
151. la VICW 325 bs ie bie hee hea aoe HE ao eee ROR cate eb nabs es 14 Using zoom buttons to change scale 0 0 00 14 Zoom to selection 2 cae eee eee eee eed eb eee ee 16 Zoom to entire aXiS eode ee eb eee be bee ee bee eee 16 Making a spectrogram Slice cece cece cee cee e eee e ee eeee 17 Linkage between spectrogram and spectrogram slice views 19 Unlinking and linking views 0 cece eee cece eee e eee e eee eees 20 Unlinking a view via the contextual Menu 1 ee 20 Restoring or creating new linkages 0 0 0 c eee tee 21 Creating a new linkage group 1 6 eee ae 23 Other linkable properties 000 eee 23 Controlling how views are displayed ccc cece cece eee ees 23 Hiding and showing ViCWS 0 0 0 tenes 23 Deleting a VEW eeren ees Gad Seo ake Bade wea EREE pes Aue Rada ees 24 Raven 1 2 User s Manual i Chapter 2 Changing the order in which views are displayed 2 0 00 24 Hiding and showing window components 000 cece eee eee 25 Selections and measurements cece cece eee cee e eee eee eees 26 About Selections orar EEEE ea plant Se Oe baa EOE i a dan AES 26 Creating and modifying range selections 0 0 00 e eee eee 27 Selection control points osassa a 00 tee 27 Committed vs uncommitted selections 00 0 0 cc ee 28 THEACUVE solecon ie ene heat arn pee yard OPE a Sa ee ae eae 28 Point Se l
152. labelled Use specified values as defaults before you click OK then Raven will automatically enter those values in the corre sponding fields when annotating subsequent selections When Raven enters default values in this dialog box you can either change the values or just press lt Enter gt or click OK to accept them gt F 25 Annotate Selection 4 x Song Type Individual ID _ Use specified values as defaults v Show this dialog whenever a selection is committed Figure 4 2 The Annotate Selection dialog box Two annotation col umns have been defined named Song Type and Individual ID Raven 1 2 User s Manual Chapter 4 Selections and Measurements Entering annotations directly in the selection table To enter an annotation value for a particular selection you can click on the annotation cell in the selection table and then type the annotation value followed by lt Enter gt To enter the same annotation value into a series of consecutive entries in a selection table 1 Enter the annotation for the first entry in the series 2 Highlight the annotation cells for a series of consecutive rows begin ning with the row for which the annotation has been entered 3 Choose Fill Selected Cells gt Down from the contextual menu for the annotation column or press Ctrl D Window or Command D Mac OS To fill a series of consecutive annotation cells with the value in the bottom cell choose
153. lculate and display real time spectrogram slice views of the signals and unlink or link views while you re recording just as in any other sound window Depending on the Raven 1 2 User s Manual 47 Chapter 1 Getting Started Other operations while recording While recording is stopped More about recording speed of your computer performance may begin to degrade with multiple views particularly if they are displayed at a large size You can make selections in the incoming signal You can zoom in on any view and display multiple lines You can even print what s on the screen the display pauses while Raven formats the current window for printing but recording continues in the background You can in fact do anything with the recorder window that you can do with any other sound window See the relevant sections earlier in this chapter for how to perform each of these tasks When you stop a recording the most recent part of the signal remains dis played on the screen You can do anything with this signal fragment that you can do with a signal in any other sound window save it make selec tions from it compute spectrograms of it print it whatever you like Remember that if you have been recording for a while you will only have the latest part of the signal to work with only what can be displayed not everything since you began recording Chapter 2 Signal Acquisition Recording covers the recording proces
154. le size the saved signal will retain the smaller dynamic range and audible quantization hiss of the 8 bit signal This is because the quantization noise is scaled along with the desired signal when 8 bit signals are scaled to the larger sample size b Although you can acquire a signal with 8 bits and then save it Storage requirements 158 The increased frequency bandwidth obtainable with higher sampling rates and the increased dynamic range obtainable with larger samples both come at the expense of the amount of memory required to store a dig itized signal The minimum amount of storage in bytes required for a Raven 1 2 User s Manual Appendix A Digital Representation of Sound digitized signal is the product of the sample rate in samples sec the sam ple size in bytes one byte equals 8 bits and the signal duration sec onds Thus a 10 second signal sampled at 44 1 kHz with 16 bit 2 byte precision requires 882 000 bytes 10 sec x 44 100 samples sec x 2 bytes sample or about about 861 Kbytes of storage 1 Kbyte 1024 bytes The actual amount of storage required for a signal may exceed this minimum depending on the format in which the samples are stored The amount of time that it takes Raven to calculate a spectrogram of a sig nal depends directly on the number of samples in that signal Thus spec trograms take longer to calculate for signals digitized at higher rates However the sample size at
155. llocates a relatively small heap enough to display the Raven window with no files open As you open files create views and perform other operations that require memory more memory is allocated to the heap as needed by the JVM When you delete views or close sound windows the memory that was used for those objects becomes available to Raven for re use By default the maximum heap size that the JVM can allocate is 256 mega bytes If Raven requests additional memory e g to open another sound file or to add a view to an existing sound window when the heap has already grown to its maximum size an out of memory error will occur An out of memory error can also occur with a smaller heap size if there is not enough memory available in your computer for the JVM to allocate the 1 The actual amount of memory available to Raven is slightly less than the heap size since part of the heap is used by the JVM itself 138 Raven 1 2 User s Manual The Memory Manager window Chapter 5 Advanced Raven Usage maximum heap size This can happen if your computer does not have enough physical memory installed or if large amounts of the installed memory are in use by other programs When an out of memory error occurs Raven will ask if you want to use the Memory Manager to release some memory Memory usage summary The top portion of the Memory Manager window Figure 5 18 displays summary information about Raven s current memory usage e M
156. llogram or graph of the sound showing amplitude versus time The spectrogram lower view represents time on the horizontal axis frequency on the vertical axis and relative power at each time and frequency as a color by default grayscale value Spectro gram views are discussed further in Chapter 3 Spectrographic Analysis In addition to waveforms and spectrograms Raven can also display spec trogram slice views of a signal and selection spectrum views which show the average spectrum of a selected portion of a signal Spectrogram slice views and selection spectrum views are discussed in Making a spectro gram slice on page 17 and in Chapter 3 Spectrographic Analysis Chapter 6 Preferences Customizing Raven explains how to configure Raven to display combinations of views other than the default waveform and spectrogram when a signal is first opened Raven 1 2 User s Manual 5 Chapter 1 Getting Started The units used on the axes are indicated in the lower left corner of each view In the waveform the units are seconds S for the horizontal time axis and kilounits kU for the vertical amplitude axis The units dis played on the vertical axis of a waveform view are the actual sample val ues in the signal which are proportional to the sound pressure at the microphone when the sound was recorded In the spectrogram the units are seconds S for the horizontal time axis and kilohertz kHz for the ver
157. lowing topics e Opening multiple files either as sound file sequences or in separate windows e Working with multi channel sounds e Correcting the sampling rate for sounds played slower or faster than normal speed during acquisition e Setting the scale and position of view axes e Creating new spectrographic views linked by spectrogram parameters to existing views e Filtering and amplifying sounds e Editing color schemes e Using the Memory Manager Opening multiple sound files in separate windows You can open more than one sound file at a time with each sound appear ing in a separate window by choosing multiple files from within the Open Sound Files dialog To display the Open Sound Files dialog choose File gt Open Sound Files There are three ways to choose multiple files to open e Click on the name of the first file you want to open in the list of files Then select additional files to open by clicking on their names while holding down the Ctrl key The names of all of the files you clicked will be highlighted and will be shown in the File Name field Each file name in the File Name field will be enclosed in double quotation marks Fig ure 5 1 If the names of the files you want to open are listed consecutively with no intervening file names in the file list click on the name of the first file to open then shift click on the name of the last file The names of the two files you clicked and all files between
158. lphin digitized at 48 kHz The period between clicks is about 1 4 mS corre sponding to a frequency of about 720 Hz 1 0 0014 The two spectro grams differ only in window size and hence bandwidth In both spectrograms hop size 208 mS window Hamming a Bandwidth 3121 Hz window size 20 points 417 mS overlap 50 In this representation each click appears as a broad band vertical stripe on the spectrogram because the window size is short enough to resolve individual clicks b Waveform When played at normal speed the sig nal sounds to a human like a buzz c Bandwidth 61 Hz window size 1024 points 21 3 mS overlap 99 In this representation indi vidual clicks cannot be resolved because each window encompasses about 15 clicks instead the click repetition frequency appears as a series of horizontal bands spaced 720 Hz apart the click repetition fre quency Time grid Window Hop size refers to the time interval measured either in samples or in time g p pP 82 Overlap and Hop Size units such as seconds or milliseconds between the beginnings of succes sive windows or records In an unsmoothed spectrogram see Smoothed vs unsmoothed display on page 92 the hop size can be seen as the width or duration of the individual cells in the spectrogram Figure 3 10 Hop size can be smaller than the window size because successive windows can overlap each other Windows can also be contiguous 0
159. lues of the samples represented at the time of the mouse position as in Figure 1 4 Later you will see how to zoom in so that individual points can be represented accu rately As you move the mouse pointer over the spectrogram view the time and frequency of the pointer s location and the relative power at that time and frequency are shown in the mouse measurement field Figure 1 5 Most commands buttons and scroll bars that affect views apply only to the active view Only one view in a sound window can be active at any given time The active view is identified by a colored vertical view selection button at its left edge The name of the active view is also highlighted on the side panel s Layout tab In Figure 1 4 the waveform is the active view in Figure 1 5 the spectrogram is the active view To activate a view click on its view selection button or in its axis areas You can also activate a view by clicking on its name in the side panel s Layout tab region i e above and to the right of the axes doing so will create a selection Selections are discussed in Selections and measurements on page 26 b Although you can activate a view by clicking in the data When a spectrogram view is active the brightness and contrast controls on Raver s control toolbar become active too Figure 1 6 y ddaliai slider addi slider re 60 a 20 Brightness value Contrast value Figure 1 6 Spectrogram bri
160. m may provide a more visually satis fying image In an unsmoothed spectrogram each actual data point on the spectrogram grid is represented by a rectangular gray box The width and height of the boxes depend on the hop size and frequency grid spacing respectively see Time grid Window Overlap and Hop Size on page 82 and Frequency grid spacing and DFT size on page 84 In an unsmoothed spectrogram the horizontal center of each box is located at the time that is halfway through the set of samples from which that spectrum was made see Time alignment of spectrogram data on page 90 The vertical center is located at the center frequency of the band pass filter whose output power is represented by the darkness of the box The size and visibility of the boxes on the screen depends on the size of the entire spectrogram on the screen which in turn depends on the size of the sound window and the signal length which affects the time dimension only and on the display scale determined by the zoom controls Figure 3 17 shows an unsmoothed spectrogram of the entire time and frequency range of a 1 8 second signal and a portion of the spectrogram after a zoom individual cells of the spectrogram are indistinguishable in the full scale view but are clearly visible in the magnified portion Raven 1 2 User s Manual 93 Chapter 3 Spectrographic Analysis 94 kHz Figure 3 17 Unsmoothed spectrogram views at two different m
161. me acquisition starts as discussed below For file sequences you must specify a file name template that Raven uses to build a unique name for each file in the sequence A file name template contains some combination of date time and sequence number tags Table 2 1 When each file in a sequence is created Raven substitutes the Raven 1 2 User s Manual Chapter 2 Signal Acquisition Recording corresponding value for each tag in the template to generate the file names Table 2 1 Date time and sequence tags used in acquired file names Minimum and maximum values for date and time tags are shown in brackets Tag Definition lt yy gt year 2 digits minimum lt 11 gt month 1 12 2 digits minimum lt dd gt day 1 12 2 digits minimum lt hh gt hour 0 23 decimals permitted 2 digits minimum lt mm gt minute 0 59 decimals permitted 2 digits minimum lt ss gt second 0 59 decimals permitted 2 digits minimum lt n gt integer sequence number starting at 1 The date and time values substituted for tags in the template depend on the Start Time setting as discussed under Start Time on page 60 The number of characters that occur within a date time or sequence tag determine the number of characters that are written to represent that unit in the file name For example if the template is setl lt nn gt the resulting filenames will end with two digit sequence
162. menu listing the presets in the corresponding folder To apply a saved measurement preset to the selection table choose the name of the preset from the Preset menu in the Measurement Chooser dialog and click OK S Measurement Chooser Rayen x Preset Displayed Measurements Available Measurements Begin Time Delta Time End Time Delta Frequency Low Frequency Peak Amplitude High Frequency Peak Time Max Amplitude Max Time Min Amplitude Figure 4 4 The Measurement Chooser dialog box Raven 1 2 User s Manual 103 Chapter 4 Selections and Measurements Visibility of view and channel entries Sort order of view and channel entries 104 If you make changes to the list order format or precision of measure ments displayed in a selection table to which a saved preset has already been applied you can save the changes under the same name by opening the Measurement Chooser and choosing Preset gt Save Preset Name The selection table displays one row for each visible view of each visible channel of the signal Figure 4 5 To hide entries for a view or a channel in the table turn off display of that view or channel in the side panel s Layout tab iy Sound 3 BlackCappedVireo aif Figure 4 5 A signal window for a single channel signal showing three selections for two views sorted by selection then by view Compare the sort order to that show
163. mitted range selection The bottom right control point is active The top right control point is the extender point Committed vs uncommitted selections When you first create a selection it is uncommitted An uncommitted selec tion is temporary it disappears as soon as you click somewhere else in one of the sound window s views to create a new selection Thus there can only be one uncommitted selection in a sound window at any one time To commit a selection press the lt Enter gt key when any one of the selection s control points is active Once a selection is committed it will persist in the signal until you explicitly clear it When you commit a selection its border changes from a dashed to a solid line The active selection When you first create a selection it is active After a selection has been committed it becomes inactive when you define a new selection which then becomes active Thus only one selection at most can be the active selection Active and inactive selections are highlighted in different colors By default the active selection is highlighted in red inactive selections are highlighted in cyan Figure 1 24 Only the active selection has control points Certain operations such as playback zoom and editing apply only to the active selection To activate an inactive selection point to the selection and choose Activate Selection from its contextual menu Raven 1 2 User s Manual Chapter 1 Getti
164. more depth in Chapter 3 Spectrographic Analysis Sound 8 SpottedHyena aif Parara Haye 20 216 1 000 2 000 2 500 gt Figure 1 13 sound window containing waveform spectrogram and spectrogram slice views The spectrogram slice shows intensity of each frequency at the point in time indicated by the time position marker in the spectrogram Click on the New Spectrogram Slice View button on the control toolbar Figure 1 14 choose View gt New gt Spectrogram Slice View or type lt Ctrl L gt Windows or lt Command L gt Mac OS The Configure New Spectrogram Slice View dialog box appears Figure 1 15 Raven 1 2 User s Manual 17 Chapter 1 Getting Started New et ti ii selection spectrum E lu lu New waveform New spectrogram slice Figure 1 14 The New View buttons This dialog box lets you specify various parameters that affect the appear ance of the spectrogram For now don t worry about what these parame ters mean they are explained in detail in Chapter 3 Spectrographic Analysis Click OK to accept the default settings and compute the spec trogram slice view 006e Configure New Spectrogram Slice View Preset p Window Size 512 samples Ea 3 dB Filter Bandwidth 124 Hz 4 y 656 Time Grid Frequency Grid Overlap 50 percent E DFT Size 512 samples 5 Hop Size 256 samples F S Grid Spacing 86 1 Hz L Averaging 1 s
165. mplitude mea surement the sample size or bit depth Aliasing and the Nyquist frequency 154 Raven s Configure Recorder dialog box enables you to choose the sam pling rate at which a signal is to be digitized The choices available are determined by the digitizer hardware and the program called an audio input plug in in Raven that controls the digitizer most digitizers have two or more sampling rates available Commercial digital audio applications use sampling rates of 44 1 kHz for audio compact discs or 48 kHz for digital audio tape Once a signal is digitized its sampling rate is fixed In order to interpret a sequence of numbers as representing a time varying signal one needs to know the sampling rate Thus when a digitized signal is saved in a file format that is designed for saving sound information such as AIFF or WAVE information about the sampling rate is saved along with the actual data points comprising the signal The more frequently a signal is sampled the more precisely the digitized signal represents temporal changes in the amplitude of the original signal The sampling rate that is required to make an acceptable representation of a waveform depends on the signal s frequency More specifically the sam pling rate must be more than twice as high as the highest frequency con tained in the signal Otherwise the digitized signal will have frequencies represented in it that were not actually present in the o
166. n always use File gt Printer Page Setup b If you click on the printer Properties button in the Print dialog To save an image of all or part of the Raven window into a graphics file choose File gt Export Image Of A submenu appears showing the four graphics objects that Raven can copy the entire Raven window the active sound window all views within the active sound window or the active view of the active window Choose whichever object you want to export from the submenu In the Export Image dialog box that appears choose a graphics file format Any of the four graphics objects can be saved in PNG TIFF JPEG or BMP format Views can also be saved in EPS format To copy an image of all or part of the Raven window so that you can paste it into a document in another program choose Edit gt Copy Image Of A submenu appears showing the four graphics objects that Raven can copy the entire Raven window the active sound window all views within the active sound window or the active view of the active window Choose whichever object you want to copy from the submenu The copied image can be pasted into documents in any program that can paste graphic images Recording a sound acquiring input Selecting an audio input device Raven obtains its audio input from an audio source e g a tape recorder CD player or microphone connected to a particular port on an audio input device installed on your computer e g microph
167. n in Figure 4 6 By default Raven sorts the entries in a selection table first by selection number then by view and finally by channel This default sort order is illustrated for a single channel signal in Figure 4 5 You can choose a dif ferent sort order e g by View Channel Selection from the Sort Rows By menu in the selection table s contextual menu Figure 4 6 shows selections sorted by view then by selection for a single channel signal Raven 1 2 User s Manual Renumbering selections Chapter 4 Selections and Measurements Selection Table sellableSortOrderSelections txt t Selection View Channel Begin Time End Time Low Freq High Freq 5 5 Hz Hz 4 410 4 573 2015 3 9365 3 4 676 4 931 1304 0 5334 7 5 130 5 372 1304 0 7468 5 4 410 4 573 2015 3 9365 3 4 676 4 931 1304 0 5334 7 5 130 5 372 1304 0 7468 5 O TH itt ttt h ek d ed d d d d d d Figure 4 6 The same selections shown in Figure 4 5 sorted by view then by selection You can also choose to have the selection table sorted in ascending order of any one of the displayed measurements by clicking on the column header for that measurement To sort in descending order shift click on the header When you initially create selections Raven assigns selection ID number in the order that you create the selections beginning at 1 To renumber selec tions beginning
168. n the display of data in real time views Display latency vs processing latency When a recorder is running you may observe a flickering gray band at the right hand edge of some real time views This band is more evident in recorder windows that are displayed at large sizes or that contain many views when the time axis is zoomed in and on slower computers This band represents the view s processing latency which is the difference between the current time by default the right hand edge of the window and the last time for which Raven has displayed data in the view The pro cessing latency is always greater than zero because it takes some time for Raven to build the visual image of the data to be displayed in the view Real time views scroll at a fixed rate irrespective of the rate at which Raven builds images for display When a view scrolls and no new image data are available for display Raven draws a gray band to fill in the time interval for which the image is not yet available As soon as the image is computed it replaces the gray band Processing latency is typically longer for spectrogram or spectrogram slice views than for waveforms because spectrograms require more calculation than waveforms The processing latency hence the width of the gray band varies from moment to moment for each view as Raven rapidly switches among the various tasks involved in updating the views in the recorder window When the processing latency is small
169. nalysis fixed for a given digitized signal and a parameter of the STFT called DFT size The relationship is frequency grid spacing sampling frequency DFT size where frequency grid spacing and sampling frequency are measured in Hz and DFT size is measured in samples DFT size is constrained to be a power of 2 that is greater than the current window size The DFT Size and frequency Grid Spacing fields in the Configure Spectro gram dialog box are linked you can specify the frequency grid spacing either directly by choosing a value from the Grid Spacing drop down menu or you can choose a value from the DFT Size drop down menu The DFT Size menu displays powers of 2 greater than or equal to the cur rent window size Larger DFT sizes correspond to smaller frequency grid spacings Lock DFT Size Next to the DFT Size drop down menu is a button marked with a padlock icon When this button is unlocked the default Raven adjusts the DFT size as you change the window size in order to maintain a consistent rela tionship to the window size subject to the constraint of being a power of 2 For example in the default spectrogram parameters the DFT size is the smallest power of 2 greater than or equal to the window size If you increase the window size from 512 to 513 Raven changes the DFT size from 512 to 1024 If you manually choose the DFT size to be for example the second power of two greater than or equal to the window size e g w
170. ne views on page 37 automatically changes the num ber of lines displayed for any other views that are linked by Number of Lines By default all views in a signal that display a time axis are linked to each other by Number of Lines Additionally spectrogram spectrogram slice and selection spectrum see Chapter 3 Spectrographic Analysis views can be linked by spectro gram parameters If two views are linked by spectrogram parameters then changing the parameters for either view automatically changes both views they are in different signal widows This can be useful for example in setting views of different signals to the same scale b Views that share a linkable property can be linked even if Controlling how views are displayed Hiding and showing views Using tools and commands in the side panel s Layout tab and in the View menu you can rearrange the order of views and hide or show the non data components of views such as the axes and position markers Click on the Layout tab in the side panel If the side panel is not dis played click on the right pointing triangle at the top Windows or bottom Mac OS of the separator bar along the left edge of the Raven window The upper portion of the Layout tab contains a list of all of the views in the active sound window Figure 1 19 Views are listed in the same top to bottom order in which they are displayed in the sound window To hide or show a view
171. ng Started yi S 1 2 3 4 5 kHz Figure 1 24 A spectrogram showing multiple selections The commit ted active selection is outlined in red inactive selections are outlined in cyan Point selections A point selection is created by clicking without dragging the mouse in a view A point selection is always shown in a waveform view as a colored vertical line The appearance of a point selection in a spectrogram or spec trogram slice view depends on which type of view was clicked to create the selection If a point selection is created by clicking on a waveform it is shown on spectrogram views as a colored vertical line Figure 1 25 This is because a point selection created in a waveform includes all frequencies by default In a spectrogram slice view such a selection would appear as a highlighted rectangle covering the entire spectrum that is visible only when the view s time position is at the time of the selection If a point selection is created by clicking on a spectrogram or spectrogram slice view it s shown as a colored symbol in spectrogram views and as a vertical line in spectrogram slice and waveform views Figure 1 25 A point selection is visible in a spectrogram slice view only if the view is positioned at the time of the selection Raven 1 2 User s Manual 29 Chapter 1 Getting Started a re 0 000 ae 10 15 25 0 311 T Selection Selection2 Selection
172. ns in Chapter 4 page 110 values for 1 proceed b If you try to save a selection table file that does not include Begin Time High Frequency Raven will warn you that you won t be able to retrieve the selections later and will ask if you want to End Time Low Frequency and If the selection table contains any unsaved changes Raven displays an asterisk at the left end of the selection table s title bar Raven 1 2 User s Man ual 33 Chapter 1 Getting Started Editing a sound Cut Copy Paste Raven lets you cut copy or delete data in the active selection using com and Delete mands on the Edit menu or standard keyboard equivalents When you cut 34 or copy a selection a copy of the selected data is put in the clipboard in a cut the selected data are then deleted from the sound and the window is redrawn to reflect the change The Paste command inserts the contents of the clipboard at the time of the active selection in the active sound win dow If the active selection is a range rather than a point the clipboard contents replace the data in the selection If there is no active selection the Paste command is unavailable Data on the clipboard can be pasted into the same sound window or a different one You can create a new empty sound window for pasting data copied or cut from an existing sound win dow by choosing File gt New Sound Window or by typing lt Ctrl N
173. nter on the second spectrogram activate the con textual menu and choose Unlink View gt Time Scale Now try using the zoom buttons to change the time scale of the first spec trogram Notice that the time scales of the waveform and the first spectro gram change together but the time scale of the second spectrogram does not change If you activate the second spectrogram and zoom in time its time scale changes while the time scales of the waveform and the first spectrogram remain unchanged If you scroll any of the three views their position markers will move in synchrony because all three are still linked by time position To restore linkages between views that have been unlinked or to create linkages between views that have never been linked activate the Linkage tab in the Raven side panel If the side panel is not visible click on the right pointing triangle at the top Windows or bottom Mac OS of the separator bar at the left edge of the Raven window Raven 1 2 User s Manual 21 Chapter 1 Getting Started 22 At the top of the Linkage tab there is a drop down menu showing all of the linkable properties of the current views Click on this menu and choose Time Scale If you created two spectrograms and unlinked them as described above the tab will display three folder icons representing link age groups with names like Group 1 Signal 1 Default and New Figure 1 18 The second group may be called
174. numbers while set1 lt nnn gt would result in filenames ending three digit sequence numbers Raven 1 2 User s Manual 59 Chapter 2 Signal Acquisition Recording Start Time File name collisions 60 For hour minute second and date tags you can specify decimal values See Table 2 2 for examples Table 2 2 Examples of file names generated by various file name templates assuming a start time of 10 30 00 and a file size of 20 seconds Template Resulting file names BCV lt hh gt lt mm gt lt ss gt aif BCV 103000 aif BCV 103020 aif BCV 103040 aiff BCV 103100 aif BCV lt hh gt lt mm mm gt aif BCV 1030 00 aif BCV 1030 33 aif BCV 1030 67 aif BCV 1031 00 aif BCV lt hh hhhh gt aif BCV 10 5000 aif BCV 10 5056 aiff BCV 10 5111 aif BCV 10 5167 aif BCV lt n gt aif BCV 1l aiff BCV 2 aif BCV 3 aif BCV 4 aif BCV lt nnn gt aif BCV 001 aif BCV 002 aif BCV 003 aif When you enter a filename containing date or time tags the string labelled Example below the Audio File s field shows what the filename would be once the relevant date and time values are substituted for the tags You can either specify that Raven use the date and time given by the com puter s internal clock Now or you can specify some other date and time Times are specified using a 24 hour representation 1 PM would thus be r
175. o prevent aliasing is to pass the analog signal through a low pass filter called an anti aliasing filter before digitizing it to remove any energy at frequencies greater than the Nyquist frequency If the origi nal signal contains no energy at frequencies above the Nyquist frequency or if it contains only low level broadband noise this step is unnecessary Raven 1 2 User s Manual Appendix A Digital Representation of Sound Sample size amplitude resolution The precision with which a sample represents the actual amplitude of the waveform at the instant the sample is taken depends on the sample size or number of bits also called bit depth used in the binary representation of the amplitude value Some digitizers can take samples of one size only others allow you to choose usually through software between two or more sample sizes Raven s default audio input device plug in allows you to choose between 8 bit and 16 bit samples An 8 bit sample can resolve 256 28 different amplitude values a 16 bit converter can resolve 65 536 2 values Sound recorded on audio CDs is stored as 16 bit samples When a sample is taken the actual value is rounded to the nearest value that can be represented by the number of bits in a sample Since the actual analog value of signal amplitude at the time of a sample is usually not precisely equal to one of the discrete values that can be repre sented exactly by a sample there is some digitiz
176. o some channels and not to others If a sound window contains any data you can paste into it only if the number of channels in the window is the same as the number of channels of data that were placed on the clipboard by a Copy or Cut operation If a sound window is empty either a new window or one from which all data have been deleted its number of channels is undefined and you can paste any number of channels into it sound cannot be changed To discard one or more channels from a sound select the channels you want to retain copy the desired data then paste the data from the selected chan nels into a new sound window b If a sound contains any data the number of channels in the Selecting channels for editing operations By default all editing operations apply to all channels If you want an operation such as copying to apply only to some channels you must first select those channels for editing To select a channel for editing hold down the Ctrl key and click in the view selection button of the active view for that channel When a channel is selected its view selection button is yellow To select additional chan nels Ctrl click in their view selection buttons To un select a channel that is already selected Ctrl click again on its yellow selection button You can also select and un select channels by clicking on their respective numbers Raven 1 2 User s Manual 125 Chapter 5 Advanced Raven Usage in th
177. ogram slices 47 spectrograms 47 waveforms 47 real time views during signal acqusition 63 Reclaim button 140 reclaiming unused memory 140 Record button 46 52 record length 167 Record To drop down list 52 recorder presets 62 default 145 recorder windows 47 51 63 66 See also recording a signal editing in 67 progress bar 63 64 reconfiguring 67 Record to Disk button 63 64 Record to Memory button 63 64 Stop Recording button 64 Stop Recording to Disk button 64 188 recorders 51 creating 52 parameters 52 recording a signal 45 48 51 See also Configure New Recorder dialog box recording modes buffer size 54 channels choosing 53 display configuration 54 56 display latency 55 file size 57 input configuration 52 53 latency 55 processing latency 55 recorder presets 62 recording buffer 54 recording level 65 recording parameters 52 retroactive 64 sample format 53 sample rate 53 sample rate conversion during 69 70 sample size 53 57 speed correction 67 68 to a file sequence 61 to file s 56 64 to memory 64 update rate 54 window presets and recorder windows 55 recording modes 51 52 choosing 52 record to file 52 record to file sequence 52 record to memory 51 records in short time Fourier transform 166 records in spectrographic views 74 Record to Disk button 63 64 Record to Memory button 47 63 64 rectangular window function 77 Re
178. om each other by the lt tab gt character These columns can appear in the file in any order If the file also contains a Selection column Raven will assign the selection numbers saved in that column otherwise the imported selections are numbered consecutively starting at 1 Column headers for other measurements may be present or absent Raven ignores values in other columns Subsequent lines in the file must contain valid entries for each of the col umns identified in the header row separated from each other by lt tab gt characters If any of the selection bounds given in a selection file is outside the limits of the active signal e g a time beyond the end of the signal or a frequency greater than the Nyquist value Raven will alert you to this and ask whether to abort importing selections If you choose to continue selec tions with bounds outside of the signal limits are ignored This section briefly defines all of the measurements available in Raven Measurements are listed alphabetically The name of each measurement is followed by a parenthesized list of the view types to which the measure ment applies Begin Time all view types The time at which the selection begins Units seconds Delta Frequency all view types The difference between Low Frequency and High Frequency for the selec tion Units Hz Delta Time all view types The difference between Begin Time and End Time for the selection Uni
179. om of the window refer to the horizontal axis of the active view for the current page b Don t confuse the functions of the two horizontal scrollbars in Moving the page incrementally the Page and Step buttons The Page Forward Page Back Step Forward and Step Back buttons Fig ure 5 5 move the current page to a new location within the entire signal by large or small increments The amount that the page moves forward or back through the signal depends on the values that were entered in the Page increment and Step increment fields of the Configure New Sound dialog box see Configuring a new paged sound window on page 120 By default paging forward or back moves the page by 90 of the page size resulting in a 10 overlap between successive pages Stepping for ward or back moves the page by 10 of the page size by default resulting in a 90 overlap between successive pages Jumping directly to a particular time within a signal To jump to a particular page start time within the entire signal enter a time value in the Page Start Time field in the page navigation panel Fig ure 5 5 and press lt Enter gt You can enter a time either in units of seconds or minutes and seconds or hours minutes and seconds The latter two formats use colons to separate the units for example 1 02 03 to repre sent 1 hour 2 minutes and 3 seconds The current file indicator jumping to a particular file in a sequence For file seq
180. on all tabs first configure all of the parameters on all of the tabs in the dialog the way you want to save them then choose Preset gt Audio Recorder gt Save As from the dialog s menu bar When the Save Audio Recorder Preset dialog appears enter a name for the preset and click OK Audio recorder presets must be saved in the folder Pre XK sets Audio Recorder within the Raven program folder You can also create additional folders within the Audio Recorder folder by clicking on the New Folder icon within the Save Sound Window dialog These folders will appear as submenus in the Preset gt Audio Recorder menu with each submenu listing the presets in the corresponding folder To save a preset for a single tab configure the parameters on that tab then choose Preset gt tab name gt Save As from the dialog s menu bar For example to save a preset for the Input tab choose Preset gt Audio Recorder Input gt Save As When the Save dialog appears enter a name for the preset and click OK To retrieve a preset for the entire recorder dialog choose Preset gt Audio Recorder gt preset name To retrieve a preset for the current tab choose Preset gt tab name gt preset name When you retrieve a preset all of the spectrogram parameters in the Configure Recorder dialog or in the cur rent tab are immediately set to the saved values If you then change some parameters and want to revert to the saved values ch
181. one or line input port of an internal sound card or USB sound input device Raven can acquire a signal directly to a file to a sequence of files or to memory only without saving to disk While Raven is acquiring input you can see multiple views waveforms spectrograms spectrogram slices scroll by in real time This section covers acquiring a signal to memory Recording to a file or file sequence is discussed in Chapter 2 Signal Acquisition Recording That chapter also covers decimating the input signal acquiring it at a lower effective sample rate You use controls supplied by the operating system to choose and config ure the audio input device that Raven will use Appendix C Configuring Audio Input discusses how to choose a particular audio input device on Raven 1 2 User s Manual 45 Chapter 1 Getting Started The Configure New Recorder dialog box 9 each operating system Before proceeding further you should refer to the Appendix to ensure that your system is properly configured Connect an audio source e g tape recorder CD player or microphone to the appropriate port of the audio input device you selected To set up Raven to acquire a signal click on the Record button on the con trol toolbar Figure 1 4 page 5 press lt Ctrl R gt Windows or lt Command R gt Mac OS or choose File gt New Recorder Raven displays the Con figure New Recorder dialog box Figure 1 33 Fiel
182. ons 110 Open Sound File Sequence 118 Open Sound Files 1 Open Workspace 44 Raven 1 2 User s Manual Index Print Sound N gt To Printer 44 Printer Page Setup 44 Save Sound N 43 Save Sound N As 43 Save Active Selection As 107 Save Selection Table As 33 Save Workspace As 44 file name collisions recording to file s 60 File Name tab Configure New Recorder dialog box 57 file name templates 58 File Names tab Configure New Recorder dialog box 61 file naming recording to file s 57 59 file sequences 117 120 choosing files individually 119 Cut operations 117 Delete operations 117 Edit operations 117 individual file selection 119 list files 117 119 Paste operations 117 Filter gt Around Edit menu 128 filter bandwidth 80 Filter Out Edit menu 128 filterbank model of STFT analysis 166 filtering 128 Filtering selected frequency band 128 floor color 89 90 floor value 89 90 Format Column menu 102 frames in short term Fourier transform 166 Frequency Grid Spacing parameter 84 frequency analysis resolution 167 frequency domain 162 frequency grid spacing 84 85 172 173 selection table contextual G Graphics export See Image export 45 gray background in views 13 grid spacing 169 See also time grid spacing frequency grid spac ing Group By Time 38 40 Group By View 38 39 grouping lines views channels 38 40 G
183. oose the name of the preset from the Preset menu again If you want to save changes you ve made under the name of the last preset you loaded choose Preset gt Audio Recorder gt Save preset name or Preset gt tab name gt Save preset name Raven 1 2 User s Manual Chapter 2 Signal Acquisition Recording The recorder window real time views during recording Creating real time signal views When you click OK in the Configure New Recorder dialog a new recorder window appears on the Raven desktop Figure 2 6 with the window lay out that you specified on the Display tab If you chose recording to mem ory inthe Configure New Recorder dialog only the triangular green Record to Memory button appears at the bottom of the window If you chose recording to a file or file sequence the Record to Memory and round red Record to Disk buttons both appear at the bottom of the win dow Except for the two record buttons at the bottom of the window a recorder window looks and behaves exactly like any other Raven sound window It can contain multiple views that can be linked to each other in various ways By default a new recorder window contains a single waveform view You can make selections in a recorder window and see correspond ing measurements in the selection table Recorder 1 E L Not recording Progress indicator Record to disk button Record to memory button Figure 2 6 A new recorder window
184. ottom portion of the Memory Manager window Figure 5 18 dis plays a list of all of the sound files presently open and the size of each one in megabytes 1 megabyte Mbyte 1024 kilobytes 1 kilobyte Kbyte 1024 bytes To the left of the name of each sound e g Sound 1 Sound 2 etc is an opener icon the shape of the opener icon depends on the oper ating system under which you re running Raven Clicking on the opener icon or double clicking on the entry name expands the entry for the Raven 1 2 User s Manual 139 Chapter 5 Advanced Raven Usage sound The expanded entry contains an entry for the sound samples that constitute the signal and one entry for each view that exists for that sound e g Waveform 1 Spectrogram 1 etc Each view entry again has an associated opener icon Clicking the opener icon or double clicking the entry name for a view expands the view s entry to show an entry for the view s rendering data and in the case of spectrogram and spectrogram slice views the spectrogram data Rendering data represent the graphic image displayed in a view s pane within the signal window and thus depend in part on the size of a view s pane Changing the size of a view pane or the entire window will change the size of the associated rendering data even though the sizes of the sound samples and spectrograms do not change The memory usage list only tracks the typically large memory allocations
185. ows audio input and output controls You may see different icons in the tray depending on how your system is config ured The Volume Control dialog appears Figure C 2 showing the volume and balance settings for various audio output devices To display the controls for audio input devices choose Options gt Properties In the Properties dia log that appears Figure C 3 the Mixer device drop down menu lists all of the sound cards installed in your computer and lets you choose which one to use for audio input On many computers only a single sound card is installed its name may differ from that shown in Figure C 3 Click on Recording check the boxes next to all of the sound input devices that you may want to use on the list of volume controls at the bottom of the dialog box then click OK Raven 1 2 User s Manual 179 Appendix C Configuring Audio Input f Yolume Control Figure C 2 The Windows Volume Control dialog as it s initially dis played showing Playback controls Controls for different devices may be displayed depending on system configuration Properties O Aux M CD Player M Line In M Microphone Figure C 3 The Properties dialog for the Windows audio playback and recording devices The Mixer device name on your computer may differ from what s shown here 180 Raven 1 2 User s Manual Mac OS X Appendix C Configuring Audio Input The Volume Control dialog will be replace
186. pectra C Auto apply E Apply Reset Close Figure 1 15 The Configure New Spectrogram Slice View dialog The sound window is re drawn with an additional view pane containing the new spectrogram slice view If the time position marker of the wave form or spectrogram view is at the very beginning of the data where Raven puts it by default when opening a new signal the spectrogram slice view does not display any data Figure 1 16 To see valid data drag the time position marker to the right in either the waveform or spectro gram view Figure 1 13 For a complete explanation of why no data are visible in the spectrogram slice view when the position marker is at the start of the signal see Chapter 3 Spectrographic Analysis 18 Raven 1 2 User s Manual Linkage between spectrogram and spectrogram slice views Chapter 1 Getting Started Sound 8 SpottedHyena aif PAn denen ds 20 1 500 2 000 2 500 T v j Figure 1 16 Sound window containing waveform spectrogram and spectrogram slice views The spectrogram slice view displays no data when the time position marker is located at the start of the data before the first spectrogram in the spectrogram view To see valid spectrogram slice data drag the time position marker to the right in either the wave form or spectrogram view Figure 1 13 As you move the mouse pointer across a spectrogram slice view the mouse
187. pectrograms of a nearby northern yellowthroat and a distant yellow warbler were made with Window Type Hann Window Size 512 samples Window Overlap 50 All four are linked by time posi tion a and c Averaging 1 spectrum b and d Averaging 4 spectra When viewing a longer time span views a and b the view that uses spectrum averaging provides a clearer image especially of the faint signal from a distant bird For the more magnified image c and d the view without averaging appears clearer If you click the Apply button Raven immediately calculates and displays the spectrogram using the parameters currently displayed in the dialog without closing the dialog Clicking OK closes the dialog before calculat ing the spectrogram If the Auto apply checkbox is checked Raven immediately recalculates and displays the spectrogram each time you change any parameter in the dialog without you needing to click the Apply button For parameters that you enter by typing in a field e g Time grid spacing or window Overlap the spectrogram is recalculated when you complete an entry by pressing the lt Enter gt or lt Tab gt key or by clicking another field or control in the dia log Raven 1 2 User s Manual 87 Chapter 3 Spectrographic Analysis Spectrogram presets Spectrogram views Significance of the color grayscale values Brightness and contrast 88 You can save and retrieve sets of spectrogram
188. poral and frequency structure at each point on the grid irrespective of the spacing between these points The following sections seek to clarify the concepts of analysis resolution and grid spacing by showing examples of spectrograms that illustrate the difference between the two At each point on the spectrogram grid the tradeoff between time and fre quency analysis resolution is determined by the relationship between record length and bandwidth as discussed above According to the uncer tainty principle a spectrogram can never have extremely fine analysis res olution in both the frequency and time dimensions For example Figure B 7 shows two spectrograms of the same signal that differ in record length and hence bandwidth In spectrogram a with a Raven 1 2 User s Manual 169 Appendix B Spectrum Analysis record length of 64 points 2 9 mS bandwidth 496 Hz the beginning and end of each tone can be clearly distinguished and are well aligned with the corresponding features of the waveform However the frequency analysis resolution is poor each tone appears as a bar that is nearly 1200 Hz in thickness In spectrogram b the record length is 512 points or 23 mS filter bandwidth 61 9 Hz or about as long as each tone in the signal Most of the records therefore span more than one tone in some cases including a tone and a silent interval in other cases including two tones and an interval The result is poor time resolut
189. properties of the basic types of animal acoustic signals Cohen L 1995 Time frequency analysis Prentice Hall Englewood Cliffs NJ Hlawatsch F and G F Boudreaux Bartels 1992 Linear and quadratic time frequency signal representations IEEE Signal Processing Magazine 9 2 21 67 A technical overview and comparison of the properties of a variety of time frequency representations including spectrograms writ ten for engineers Jaffe D A 1987 Spectrum analysis tutorial Part 1 The Discrete Fourier Transform Part 2 Properties and applications of the Discrete Fou rier Transform Computer Music Journal 11 3 9 35 An excellent introduction to the foundations of digital spectrum analysis These tutorials assume no mathematics beyond high school algebra trigonometry and geometry More advanced mathematical tools e g vector and complex number manipula tions are developed as needed in these articles Marler P 1969 Tonal quality of bird sounds In Bird Vocalizations Their Relation to Current Problems in Biology and Psychology ed R A Hinde pp 5 18 Cambridge University Press Includes an excellent qualitative discussion of how the time and frequency analysis resolution of a spectrum analyzer interact with signal characteristics to affect the appearance of a sound either as a spectrogram or as an acoustic sensation Oppenheim A V and Schafer R W 1975 Digital Signal Processing Pren tice Hall En
190. pter 3 Spectrographic Analysis 98 Raven 1 2 User s Manual Chapter 4 About this chapter Selections and Measurements Annotations This chapter provides a complete reference for working with selections and measurements It builds on the introduction to selections and mea surements provided in Chapter 1 If you have not already read the section on Selections and measurements in Chapter 1 page 26 you should do so before reading this chapter The section on Measurements beginning on page 111 defines all of the measurements that are available in Raven An annotation is a user defined text string that appears in its own named column in the selection table Annotations can contain any text that you choose to enter Figure 4 1 z Sound 1 BlackCappedVireo aif z a Selection Table BlackCappedVireo selections txt Selection View Channel Begin Time End Time Ea High Freq see 2 OF Hz Hz 1126 4 9181 8 s D a 1ean 1945 A 7645 8 A i 17 724 16 927 20 621 17 973 1455 1 1126 4 1706 7 5327 2 t 9181 8 s 8601 5b Figure 4 1 A series of selections with annotations A single annotation column named Unit Type is defined Selection labels see Selection labels on page 109 have been configured to display the Selection ID and Unit Type values separated by Raven 1 2 User s Manual P 99 Chapter 4 Select
191. quisi tion To begin recording to a file or file sequence click the Record to Disk button The Record to Disk button is then replaced by the square red Stop Recording to Disk button If the recorder is not already recording to mem ory recording to memory and to a file or file sequence begins immedi ately and all views in the window begin displaying data If the recorder is already recording to memory when you click the Record to Disk button recording to memory continues and recording to the specified file or file sequence begins While recording to a file Raven displays the name of the file and a progress bar at the bottom of the recorder window to indicate how much of the file has been recorded If you re recording to a single file file record ing stops when the file has reached the size specified in the Configure Recorder dialog see File Size on page 57 If the recorder was recording to memory before file recording started it continues recording to memory after file recording stops When a file in a sequence has reached the speci fied size recording to disk continues uninterrupted with the next file and continues until you click the Stop Recording to Disk button When configuring a recorder you can use the Retroactive Recording Off set field to specify that acquisition to disk files should begin at a point in time prior to the moment when you click the Record to Disk button provided that the recorder was already recording
192. quisition Recording This chapter describes how to acquire digitize signals with Raven and assumes that you are familiar with basic Raven concepts and operations as described in Chapter 1 In order to make good recordings with Raven you should be acquainted with the basic concepts of digital sound representation discussed in Appendix A Digital Representation of Sound Failure to understand concepts such as sampling rate and sample size can lead to digitized sig nals that are poor in quality or distorted in various ways In this chapter you ll learn how to e choose whether to record to memory to a file or to a file sequence create and configure a recorder window create and work with real time signal views in a recorder window Overview of signal acquisition Recording modes Raven acquires records audio signals via recorders A recorder is repre sented on the Raven desktop by a recorder window that can display one or more views of a signal in real time as the signal is being acquired A recorder window is like any other Raven sound window except that it has additional controls for starting and stopping recording Raven provides three different recording modes which differ in where the signal is stored as it s recorded e Record to memory When recording to memory audio data are not automatically saved to disk files but reside only in a portion of Raven s temporary memory allocated as a recording buffer
193. r For each type of measurement you can specify a default display precision You can also specify a different precision for specific measurements within each type which will override the default for the type For example if you were to specify a default precision of 0 000 for time measurements and a specific precision of 0 00 for the Delta Time measurement Raven would display two digits to the right of the decimal point for Delta Time values and three digits for all other time values To specify the default measurement precision for time measurements uncomment and edit the following entry raven measurement basic time defaultValueFormat 0 000 To override the default measurement precision for time measurements and specify a different precision for Begin Time End Time Delta Time Max Time Min Time or Peak Time uncomment and edit the appropriate one of the following entries raven measurement basic beginTime defaultValue Format 0 000 raven measurement basic endTime defaultValueFor mat 0 000 raven measurement basic deltaTime defaultValue Format 0 000 Raven 1 2 User s Manual 149 Chapter 6 Preferences Frequency Amplitude raven measurement basic maxTime defaultValueFor mat 0 000 raven measurement basic minTime defaultValueFor mat 0 000 raven measurement basic peakTime defaultValueFor mat 0 000 To specify the default mea
194. r cases where more than one view of a given type exists The remaining columns in each row display measurements for the given selection and view Raven 1 2 User s Manual 31 Chapter 1 Getting Started Choosing Z Sound 2 LarkSparrow aif OS a a Figure 1 26 A sound window containing one waveform and one spec trogram view with multiple selections and the corresponding selection table By default Raven displays four measurements in the selection table Begin measurements to Time End Time Low Frequency and High Frequency These values col 32 display lectively called the selection bounds define the edges of a selection in a spectrogram view However you can choose to have Raven display any combination of measurements from a large repertoire Choosing Choose Measurements from the View menu or from the selection table s contex tual menu displays the Measurement Chooser dialog box Figure 1 27 The left list shows the measurements that are currently displayed in the selection table The right list shows all of the measurements that are available in Raven To add a measurement select the name of the mea surement in the right list and then click the left pointing arrow between the two lists to add it to the left list To remove a measurement select its name in the left list and then click the right pointing arrow Shift click to select multiple adjacent measurements in either list con
195. r of the view pane place the position marker on the point of interest then click the corresponding Center Position button Figure 1 9 The posi tion marker and the underlying data will jump to the center of the view pane Blue labels along the axes show the exact numeric values of the cur rent horizontal and vertical positions On computers running the Windows operating system WINDOWS you can make a view s horizontal position marker jump directly to a point by control clicking at that point Center vertical position Center honzontal position Figure 1 9 The horizontal and vertical Center Position buttons Notice that when you move the time position of either the waveform or spectrogram the time position marker in the other view moves with it This is because views that share a dimension e g the time dimension for waveform and spectrogram views are by default linked by their position in that dimension Linkage of views is discussed later in this chapter see Unlinking and linking views on page 20 The horizontal and vertical position of a view control four aspects of a view s appearance and behavior First a view s horizontal and vertical position in combination with the view s horizontal and vertical scales determine what portion of the view s data is visible in the window Sec Raven 1 2 User s Manual 11 Chapter 1 Getting Started ond a view s position is the point around whic
196. r to separate not the back slash Default measurement precision 148 By editing the appropriate entries in the preference file you can specify how many digits of precision Raven should use by default for displaying and saving measurements in the selection table You can always change Raven 1 2 User s Manual Time Chapter 6 Preferences the precision of a measurement displayed in a selection table as described in Measurement precision and format in Chapter 4 page 102 preset from the Preset menu within Raven s Measurement Chooser or by specifying a default measurement preset in the preference file the measurement precisions saved for measurements included in the preset will override precision preferences Measurement precision preferences will apply only to measurements that are not specifically included in the the preset when and if these are added to the selection table via the Measurement Chooser b If you invoke a measurement preset either by choosing a Measurement precision entries are of the form raven measurement basic name defaultValueFormat precision where name is replaced by the name of a measurement type or of a spe cific measurement and precision is replaced by a string such as 0 000 The number of zeros to the right of the decimal point indicates the desired precision Raven provides measurements of four types of quantities time frequency amplitude and powe
197. rec tory as the list file A relative path name can start with the name of a sub directory within the list file s directory or it can use the double dot notation to indicate the parent directory of the list file s directory For example consider a list file that resides in the directory c SoundData and contains the following four entries firstFile wav moreData secondFile wav otherSounds thirdFile wav c frogSounds fourthFile wav When opening this file sequence Raven will look for the following files Raven 1 2 User s Manual Selecting files in a sequence individually Chapter 5 Advanced Raven Usage SoundData firstFile wav SoundData moreData secondFile wav otherSounds thirdFile wav frogSounds fourthFile wav Q OF Od When specifying directories in list files the forward slash and back slash characters may be used interchangeably You can manually specify a set of sound files to open as a sound file sequence by choosing multiple files from within the Open Sound Files dia log box There are three ways to choose multiple files to open as a sequence e Click on the name of the first file you want to open in the list of files Then select additional files to open by clicking on their names while holding down the Ctrl key The names of all of the files you clicked will be highlighted and will be shown in the File Name field Each file name in the File Name field will
198. red on the analysis frequency of the filter In this filterbank model of STFT analysis the spectrogram is considered as representing the time varying output amplitudes of filters at successive analysis frequen cies plotted above each other with amplitude again represented by color by default grayscale values A spectrogram can be characterized by its bandwidth the range of input frequencies around the central analysis fre quency that are passed by each filter All of the filters in a spectrogram have the same bandwidth irrespective of analysis frequency Record length bandwidth and the time frequency uncertainty principle The record length of a STFT determines the time analysis resolution At of the spectrogram Changes in the signal that occur within one record e g the end of one sound and the beginning of another or changes in fre 166 Raven 1 2 User s Manual Appendix B Spectrum Analysis quency cannot be resolved as separate events Thus shorter record lengths allow better time analysis resolution Similarly the bandwidth of a STFT determines the frequency analysis reso lution Af of the spectrogram frequency components that differ by less than one filter bandwidth cannot be distinguished from each other in the output of the filterbank Thus a STFT with a relatively wide bandwidth will have poorer frequency analysis resolution than one with a narrower bandwidth Ideally we might like to have very fine tim
199. ribed in Color schemes in Chapter 1 page 36 You can create a new color scheme by using the Color Scheme Editor to change the color of any of the color scheme elements listed in Table 5 1 Raven 1 2 User s Manual 129 Chapter 5 Advanced Raven Usage Table 5 1 Editable elements of a color scheme active point selection active selection border active selection fill axis background gram Slice line inactive point selection inactive selection border inactive selection fill line title no data playback cursor position marker waveform dot waveform line Figure 5 12 shows an example of two color schemes that differ in spectro gram color map background color axis color and waveform line color 130 Raven 1 2 User s Manual Chapter 5 Advanced Raven Usage Figure 5 12 A sound window displayed with two different color schemes To open the Color Scheme Editor Figure 5 13 choose Color Scheme gt Edit from the View menu or from the contextual menu for any view Raven 1 2 User s Manual 131 Chapter 5 Advanced Raven Usage Choosing a color scheme element to edit Choosing colors 132 z 2 Color Scheme Editor xj Preset Color E Active Point Selection v Opacity 255 J Recent T mR mao Preview Z Auto appiy ok apy Reset close Figure 5 13 The Color Sc
200. riginal at all This appearance of phantom frequencies as an artifact of inadequate sampling rate is called aliasing Figure A 2 Raven 1 2 User s Manual Appendix A Digital Representation of Sound W 0 435 0 436 0 437 0 438 b kU z S 0 435 0 436 0 437 0 438 Figure A 2 Aliasing as a result of inadequate sampling rate Vertical lines indicate times at which samples are taken a A 500 Hz pure tone sampled at 8000 Hz The blue sinusoidal curve represents the continu ous analog waveform being sampled There are 16 sample points 8000 500 in each cycle of the waveform If the same analog signal were sampled at 800 Hz red sample points there would be fewer than two points per cycle and aliasing would result b The aliased wave form that would be represented by sampling the 500 Hz signal at a sampling rate of 800 Hz Nyquist frequency 400 Hz Since the origi nal waveform was 100 Hz higher than the Nyquist frequency the aliased signal is 100 Hz below the Nyquist frequency or 300 Hz The highest frequency that can be represented in a digitized signal with out aliasing is called the Nyquist frequency and is equal to half the fre quency at which the signal was digitized The highest frequency shown in a spectrogram or spectrum calculated by Raven is always the Nyquist fre quency of the digitized signal If the only energy above the Nyquist fre quency in the analog signal is in the form of low leve
201. ring annotations when committing selections 0000045 100 Entering annotations directly in the selection table 044 101 Using the Annotate Selection command 0 0 0c c eee 101 Creating selections in multi channel sounds 0eeeeeees 101 Configuring the selection table cece cece cee cece ee eee 102 Measurement precision and format 020 00 ee eee eee eee 102 Using measurement presets 0 0 0 0 eee 103 Visibility of view and channel entries 2 0 0 0 0 e eee 104 Sort order of view and channel entries 0 00 eee ee eee 104 Renumbering selections 0 00 cc eae 105 Working with selections cece cece cece cere cece seeeeees 105 Activating a selection from the selection table 00 00 00 eae 105 Finding the active selection 0 0 0 0 eee eae 105 Modifying selection bounds 0 0 0 0 eee eae 106 Moving selection control points 00 0c ee 106 Editing in the selection table 0 1 0 0 c ee 106 Raven 1 2 User s Manual Chapter 5 Using the Selection tab in the side panel 2 20000 2 cree 106 Modifying selection channels 000 e eee eee tees 107 Selection tables in paged sound windows 00 0 eee eee eee eee 107 Saving the active selection 0 000 eee 107 Copying selected rows from the selection table 000 00s 107 Clearing selections 6 2
202. rms A spectrogram colormap defines the relationship between power values in the spectrogram and colors used to display them Raven provides four predefined colormaps Grayscale Hot Cool and Standard Gamma itt Figure 1 29 To change the colormap of a spectrogram choose Color Scheme gt Colormap name from the spectrogram s context menu or from the View menu when the spectrogram is active by color scheme If you change the colormap or any other item in a view s color scheme the affected colors will also change in any other views that are linked to it by color scheme b Views in a sound window are by default linked to each other 1 The Standard Gamma II color map is included in Raven courtesy of Research Systems Inc a Kodak Company Raven 1 2 User s Manual Editing color schemes Multiple line views Chapter 1 Getting Started 03 0 4 0 5 0 6 0 7 Figure 1 29 Three spectrogram views of the signal CassinsKing bird wav using three different colormaps The colormaps from top to bottom are Hot Cool and Standard Gamma II You can reverse the spectrogram colormap by choosing Color Scheme gt Reverse Color Map from the spectrogram s context menu or from the View menu when the spectrogram is active To edit a view s color scheme choose Color Scheme gt Edit from the view s context menu or from the View menu when the view is active The color scheme editor is discusse
203. roportion of the entire signal is included in the current page The position of the scroll box within the scrollbar indicates the position in time of the current page within the entire signal The start time of the cur rent page is displayed below the scrollbar You can move the page to any point within the signal by dragging the scroll box As you drag the scroll box the displayed start time of the page is continually updated to corre spond to the position of the scroll box If the signal is a file sequence the name and sequence number of the file containing the start of the page are also continually updated as you move the scroll box When you release the scroll box at a new start time Raven loads the data for the new page posi tion as needed from the file or file sequence and updates the views dis played in the window Depending on the page size and the number and type of views shown there may be a slight delay while Raven updates the views Raven 1 2 User s Manual Selections spanning pages Reconfiguring paging for an existing window Chapter 5 Advanced Raven Usage Clicking in the scrollbar to the right or left of the scroll box pages forward or back equivalent to clicking the Page forward or Page back button see below a paged sound window The scrollbar in the page navigation panel at the top of a paged sound window refers to the time dimension of the entire signal The scrollbar and navigation controls at the bott
204. rouping options side panel Layout tab 38 40 H Hamming window function 77 185 Index Hann window function 77 Hanning window function 77 heap 138 hh tag in file name templates 59 Hide All window components 25 Hide All Channels 124 Hide All Views 24 Hide All Window Components 25 Hide View View menu 24 hiding showing channels 124 hiding showing views 23 High Frequency measurement 32 110 112 hop size 82 84 Hop Size parameter 82 83 HSB color chooser 133 hue 133 Image export to file 45 via clipboard 45 J Java Virtual Machine JVM 138 JPEG graphics file format 45 JVM Java Virtual Machine 138 K Kaiser window function 77 80 keyboard shortcuts x L landscape orientation for printing 44 Layout tab side panel 7 8 24 Channels list 124 Components list 25 Grouping options 38 hiding showing window components 25 Lines box 38 Views list 23 line titles 25 26 visibility and window presets 42 Lines box side panel Layout tab 38 linkable properties 22 23 linkage of views 11 19 20 22 23 creating 21 22 linkable properties 22 23 linkage groups 22 23 linked spectrographic views 128 restoring 21 22 186 unlinking views 20 21 linkage groups 22 creating 23 Linkage tab side panel 22 40 list files for file sequences 61 62 117 119 Il tag in file name templates 59 Lock DFT Size 85 Lock Hop Size in Configure Spectrogram dialog box
205. ry For example to use a spectrogram preset called MySpectrogram by default change the default spectrogram preset entry to raven preset spectrogramParameters defaultPreset MySpectrogram Spectrogram views that are created by applying a window preset will use the spectrogram parameters specified by the window preset not those in the default spectrogram preset A recorder preset saves the state of all parameters and controls on one or all of the tabs in the Configure Recorder dialog under a single preset name You can retrieve a saved recorder preset from the Preset menu within the Configure Recorder dialog Recorder presets are discussed fur ther in Using recorder presets on page 62 When Raven is first installed there is no default recorder preset defined This is because a recorder preset includes the name of the default audio input device which varies among computers and thus cannot be included in a predefined recorder preset To specify a default recorder preset you must first configure a recorder with the parameters that you will use most commonly and save that configuration as a recorder preset named Default as described in Using recorder presets on page 62 Then uncomment the following entry in the preference file by deleting the raven preset audioRecorder defaultPreset Default Raven 1 2 User s Manual 145 Chapter 6 Preferences 146 Measurement presets Sound window preset
206. rying hop size in spectrograms The signal is part of a song of a lark sparrow digitized at 44 1 kHz The three spec trograms are unsmoothed and differ only in hop size window overlap In all three spectrograms window type Hann window size 512 samples 11 6 mS 3 dB bandwidth 124 Hz frequency grid spacing 86 1 Hz DFT size 512 samples a Hop size 11 6 mS window overlap 0 b Hop size 5 8 mS window overlap 50 c Hop size 1 1 mS window overlap 90 some of the available data and can give an extremely mis leading picture of a signal Negative window overlaps should generally be avoided unless you have some specific reason for wanting to omit some parts of a signal from analysis b A spectrogram made with a negative window overlap ignores Lock Overlap vs Lock Hop Size Next to the Overlap and Hop Size fields are two buttons marked with open and closed padlock icons The button that displays the closed pad lock indicates which value window overlap or hop size will be locked or held constant when you make changes to the window size Clicking on either button reverses the state of both buttons The frequency grid spacing of a spectrogram visible as the height of the individual boxes in an unsmoothed spectrogram see Smoothed vs unsmoothed display on page 92 depends on the sample rate which is Raven 1 2 User s Manual Spectrum averaging Chapter 3 Spectrographic A
207. s Color scheme presets A measurement preset saves a list of measurements to be displayed in a selection table along with their respective formats and precisions You can retrieve a saved measurement preset from the Preset menu within the Measurement Chooser dialog Measurement presets are discussed further in Using measurement presets on page 103 Raven is installed with a measurement preset named Default which is initially specified as the default by the following entry in the preference file raven preset measurementList defaultPreset Default To change the default to a different measurement preset edit this entry For example to use a measurement preset called MyMeasurements by default change the default measurement preset entry to raven preset measurementList defaultPreset MyMeasurements measurements specified in the window preset take prece dence over the default measurement preset See Using sound window presets on page 41 b When a window preset is applied to a sound window the A sound window preset saves information about the layout of a sound window such as window size what views are displayed their sizes color schemes position and scale selection table visibility and measurements displayed You can retrieve a saved window preset from the Window Pre set menu on the View menu or the contextual menu for any view Sound window presets are discussed further in Using sound window
208. s in more depth Read that chapter to find out e how to select and configure your input device e how to record to a file or a sequence of files e how to incorporate date and time stamps into names of acquired files e how to acquire signals at lower sample rates than those available from an audio input device signal decimation Contacting the Raven development and support team 48 The Raven developers want to hear from you You can report a bug request support or suggest a feature by choosing File gt Email Feedback and sending email from within Raven Figure 1 35 Before clicking Send be sure to check that your correct email address appears in the From field so we can get back to you Although you can of course use your usual email program to contact us at raven _bugs cornell edu for bugs and feature requests or raven _support cornell edu for support or other comments there is one situation in which you should use Raven s email feedback feature 1 To configure Raven to fill in your email address automatically open the Rav enPreference txt file using any text editor and fill in your email address in the line raven feedback fromAddress yourEmailAddress yourISP Save the edited file as plain text The next time you launch Raven and use the email feedback form your address will be supplied automatically in the From field Raven 1 2 User s Manual Chapter 1 Getting Started and not another progr
209. s 53 seconds long The views are linked in time position but unlinked in time scale Unlinking the time scales makes it possible to view simultaneously an eight second portion segment of the signal upper view and a close up of a two second segment con tained within it lower view Since the two views remain linked in time position the position markers provide a reference point to show where the close up view is located within the entire signal As either view is scrolled horizontally through the signal the linked position markers iden tify the same point in time in both views Raven 1 2 User s Manual Restoring or creating new linkages Chapter 1 Getting Started S 5 6 7 8 123 9 10 11 KHZ 372 74 76 78 8 8123 84 86 88 9 Figure 1 17 Two spectrogram views of the file BlackCappedVireo aif that are linked in time position but unlinked in time scale The upper spectrogram shows 7 8 seconds of the signal the lower spectrogram is a close up of 2 0 seconds The highlighted rectangle identifies the same selection in both views The time position markers in both spec trograms identify the same time because the time positions are linked To create two spectrograms that are unlinked in time scale in this way 1 Open a signal 2 Make a second spectrogram by clicking the New Spectrogram button Figure 1 14 page 18 or typing lt Ctrl G gt Windows or lt Command G gt Mac OS 3 Place the mouse poi
210. s involved in choice of sample size Raven always represents signals internally with 16 bits per sample If you choose an input sample size other than 16 bits the input values are re Raven 1 2 User s Manual 53 Chapter 2 Signal Acquisition Recording Recording Display scaled to 16 bit samples for more on rescaling of sample values see the footnote under Sample Size on page 57 54 Buffer Size Update Rate The Display tab Figure 2 2 allows you to configure the recorder window and is displayed for all three recording modes x Preset Record To Memory Input Display Buffer Size 30 0 seconds v Update Rate 10 0 Hz Latency 0 0 seconds Window Preset Default xi Cancel Figure 2 2 The Display tab of the Configure New Recorder dialog box The buffer size determines how much of the signal is retained in memory and can be visible in the recorder window during signal acquisition You can specify buffer size either in seconds or minutes You can use the drop down list to choose time units of seconds or minutes The default buffer size is 30 seconds During recording audio data remain in memory for the duration of the buffer and are then discarded to make room for new incoming data If you re recording to memory data that are discarded from the buffer are lost permanently unless you re acquire them When recording to a file or a file sequence data that are gone from the buff
211. s not visible To expand the selection table so that it s Raven 1 2 User s Manual Chapter 1 Getting Started visible click on the upward pointing Expand Selection Table button at the left Windows or right Mac OS end of the textured separator bar along the bottom edge of the sound window If you click on the same but ton again the selection table will expand to occupy the entire window hiding the window s views Clicking on the downward pointing Collapse Selection Table button reduces the size of the selection table You can also drag the textured separator bar up or down to open or resize the selection table By default the selection table displays one row for each selection in each view of the sound Figure 1 26 Raven assigns a sequential selection ID beginning at 1 to each selection that is defined for a sound window Each selection s ID is shown in the first column of the selection table along with a colored square that indicates whether or not the selection is the active selection by default red for the active selection cyan for all others The second column labeled View displays an icon to indicate whether the row refers to a waveform spectrogram spectrogram slice or selection spectrum view The icons for the view types are the same ones used on the New View buttons in the control toolbar Figure 1 14 page 18 The number next to the icon indicates which view of a particular type the entry refers to fo
212. s the portion of a selections view that you want to select The other way to create a range selection is to click once at one edge or corner of the selection and then shift click at the opposite edge or corner In a waveform all of the time between the initial click and the shift click will be selected In a spectrogram a rectangular region will be selected with the locations of the click and shift click defin ing diagonally opposite corners Shift clicking provides a way of selecting a section that is too long to be displayed in the window at the current scale Click once at the beginning of the section and then use the scroll thumb to move the view so that the end of the desired section is visible and shift click there The entire section will be selected even though one end of the selection is beyond the edge of the window When you first create a selection the selection is displayed with a dashed border that is red by default You can change the color used to draw new selections as described in Editing color schemes in Chapter 5 page 129 By default a selection label appears near the top left corner of the selection displaying the selection ID number Selection contro points As soon as you release the mouse button selection control points appear at the edges and at the center of the selection In spectrogram views selec tion control points also appear at the corners of a selection Selection con trol points are sm
213. s you that the sound window is now displaying channel 1 of a waveform and a spectrogram view You can resize the side panel by dragging the vertical separator bar between the side panel and the Raven desktop To hide the side panel click on the left pointing arrow at the top Windows or bottom Mac OS of the separator bar To show the side panel when it s hidden click on the right pointing arrow at the top of the separator bar at the left edge of the Raven desktop If the sound window is maximized when you hide the side panel it automatically expands to occupy the entire Raven desktop The right hand end of the control toolbar contains the playback controls Figure 1 7 To play back the part of the signal that is visible in the win dow click the Play button or press lt Ctrl Shift P gt Windows or lt Com mand Shift P gt Mac OS Raven 1 2 User s Manual Playing a selected part of a signal Position markers and scrolling playback Chapter 1 Getting Started Scrolling play Play gt Dx n Rate 1 0 Playback rate Stop playback Figure 1 7 The playback controls As the sound plays a vertical green line the playback cursor moves across the waveform from left to right to show you what part of the signal you are hearing To stop playing at any time click the Stop button When the selection finishes playing or when you click Stop the playback cursor dis appears You can select a portion of a signal to pla
214. se Raven s Memory Manager window Figure 5 18 to see how much memory is used for each view of each file that is open and to release memory by deleting selected views or sound windows You can open the Memory Manager at any time by choosing Window gt Memory Manager Raven 1 2 User s Manual 137 Chapter 5 Advanced Raven Usage x Maximum Heap Size 254 MB Configure Current Heap Size 17 MB Memory Used 10 MB Memory Available 7 MB Reclaim Name Size MB 4 Sound1 6 1 Sound Samples 2 4 Spectrogram 1 3 3 Rendering Data 0 9 Spectrogram 2 4 H Waveform 1 0 4 Rendering Data 0 4 Figure 5 18 The Memory Manager window When the window is first opened the tree view shown is fully collapsed In this example the win dow would initially display only Sound 1 To expand or collapse an item in the view click on the opener icon to its left or double click the item s name About Raven Raven runs within a simulated computer called the Java Virtual Machine memory allocation JVM At any given time when Raven is running a certain amount of your computer s memory known as the heap is allocated by the JVM for use by Raven The heap represents the memory that is available for Raven s use the amount of memory that Raven is actually using at any given moment may be less than the heap size The heap can grow or shrink as Raven s memory needs change Initially when you first launch Raven the JVM a
215. se frequency measurements you will probably want to choose a large window size hence better frequency and poorer time resolution If you want better time resolution choose a shorter window size the bandwidth will then be larger poorer frequency resolution Figure 3 8 Figure 3 8 Effect of choice of window size on time and frequency smearing in spectrogram views of Cassin s kingbird sound digitized at 44 1 kHz For both views window type Hann hop size 64 samples Frequency grid spacing 22 Hz a Window size 800 samples 3 dB bandwidth 79 Hz b Window size 150 samples 3 dB bandwidth 423 Hz View a has better frequency resolution note sharpness of the nearly constant frequency bands in selection 2 but poorer time reso lution note horizontal smearing of the rapid downsweep in selection 1 and in the oscillating frequencies in the second part of the call Raven 1 2 User s Manual 81 Chapter 3 Spectrographic Analysis Figure 3 9 shows an extreme example of how choice of window size can change the appearance of a spectrogram See Appendix B A Biologist s Introduction to Spectrum Analysis for further discussion and more examples of the effect of varying window size and bandwidth Ks 0 39 0 4 0 41 0 42 c 6 a E 4 KHz s na 0 4 0 41 0 42 Figure 3 9 Effect of varying analysis resolution on spectrograms The signal is part of a rapid series of clicks produced by a spotted do
216. se pointer Under the Windows operating system contextual menus are activated by right clicking Under Mac OS X contextual menus are activated by holding down the Ctrl key while clicking MAC OS Any computer running Mac OS X can be equipped with a third party USB two button mouse A two button mouse provides access to contextual menus by right clicking in addition to use of the Ctrl key while clicking Keyboard shortcuts and menu mnemonics There are two ways to use the keyboard rather than the mouse to acti vate menu commands Some commands have single keystroke equiva lents or shortcuts activated by pressing the lt Ctrl gt Windows or lt Command gt Mac OS key and a single other key simultaneously Key board shortcuts are shown in menus to the right of the command name Figure 1 Any menu command can also be chosen by using mnemonics A menu mnemonic consists of a sequence of two or more keystrokes in which the first keystroke activates a particular menu subsequent key strokes choose particular items from within the menu To activate a partic ular menu press the lt Alt gt Windows or lt Option gt Mac OS key and the first letter of the menu name simultaneously To choose an item from the menu once it s activated press the key corresponding to the underlined letter in the item name For example to choose the Open Workspace command from the File menu Figure 1 press lt Alt F gt lt W gt Windows
217. sequence If you opened the sound in a paged window the duration in memory is the length of one page See Paged sound windows opening large sounds in Chapter 5 page 120 for more on paged sound windows Raven 1 2 User s Manual 13 Chapter 1 Getting Started Scale of a view Using zoom buttons to change scale 14 1 3 gt D Hm Figure 1 10 Waveform and spectrogram views with centered position markers positioned at the start of the signal left edge of horizontal scrollbar and the lowest frequency bottom end of vertical scrollbar of the spectrogram The vertical scrollbar refers to the spectrogram view because the spectrogram is the active view Each view that Raven displays has a horizontal and vertical scale associ ated with it The scale determines the relationship between the dimen sional units shown along that axis e g seconds or kilohertz of the view and display units e g pixels centimeters or inches on your computer screen The scale at which the entire extent of an axis just fits in the view pane is called the default scale for that axis When you first open a sound file the time scale of the waveform view is set to the default When you first create a spectrogram the frequency scale is set by default so that the entire frequency range of the signal fits vertically in the spectrogram pane In the lower right hand corner of a Raven sound window are the zoom controls for the acti
218. set Manager Figure 5 17 to delete or rename presets to create rename or delete folders within preset folders and to move pre sets from one folder to another To open the Preset Manager window do one of the following e choose Window gt Preset Manager from the Raven menu bar e choose Window Preset gt Manage Presets from the View menu or the contextual menu for any view e choose Preset gt Manage Presets from the menu bar in any dialog box that supports presets 136 Raven 1 2 User s Manual Chapter 5 Advanced Raven Usage xi Preset Type Spectrogram Parameters Default DefaultKaiser Broadband Narrowband G NarrowBand highOverlap G NarrowBand lowOverlap New Folder Figure 5 17 The Preset Manager dialog box If you access the Preset Manager from a Preset menu in a dialog box it will initially display presets of the appropriate type for the dialog box from which you invoked it To choose a different preset type to manage use the Preset Type drop down list The list box will show the names of all of the presets and folders presently defined for the selected preset type To rename or delete a preset click on its name in the list then click the appro priate button To create a folder within the currently selected preset type click New Folder To move a preset or folder into or out of a folder sim ply drag its entry within the list The Memory Manager You can u
219. sibility size which tab is selected and so on Remember that a workspace file saves the entire state of 3 Raven including all of the sound windows that are open If you just want to save the size and layout of the main Raven window save the workspaces when no sound windows are open You can specify the default directories that Raven uses when you open and save sound files selection files or workspace files When Raven is first installed these defaults are set respectively to directories named Examples Selections and Workspaces within the Raven program directory These defaults are specified by the following three entries in the preference file raven ui openFileChooser defaultDirectory Examples f raven ui selectionFileChooser defaultDirectory Selections E raven ui workspaceFileChooser defaultDirectory Workspaces The notation means that the specified directories are subdirectories of the Raven program directory You can change any of these to any direc tory on your hard disk by editing the corresponding entry in the prefer ence file For example the following entry tells Raven to use the directory c MyStuff SoundFiles as the default directory for sound files raven ui openFileChooser defaultDirectory c MyStuff SoundFiles directories and subdirectories in Raven preference entries b You need to use the forward slash characte
220. signal ampli tude is measured as voltage which is directly proportional to the sound pressure In the frequency domain the amplitude of a signal is repre sented as a function of frequency The frequency domain representation of a pure tone is a vertical line Figure B 1b Raven 1 2 User s Manual Appendix B Spectrum Analysis a Pressure b Amplitude f 1 t Frequency Hz Figure B 1 Time domain and frequency domain representations of an infinitely long pure sinusoidal signal a Time domain t is the period of the sinusoid b Frequency domain fis the frequency of the sinusoid Any sound no matter how complex can be represented as the sum of a series of pure tones sinusoidal components Each tone in the series has a particular amplitude and a particular phase relationship i e it may be shifted in time relative to the others The frequency composition of com plex signals is usually not apparent from inspection of the time domain representation Spectrum analysis is the process of converting the time domain representation of a signal to a frequency domain representation that shows how different frequency components contribute to the sound Frequency domain representations of sounds are often more intuitively interpretable because the mammalian auditory system specifically the cochlea performs a type of spectrum analysis in converting vibrations of the eardrum into neural impulses Our
221. sing Move View Up or Move View Down from the View menu or the view s contextual menu 24 Raven 1 2 User s Manual Chapter 1 Getting Started Hiding and showing The bottom pane of the side panel s Layout tab contains a list of window window components that can either be displayed or hidden Figure 1 20 You can components display or hide each component of the active window by checking or unchecking its checkbox You can show or hide all components at once by clicking on the Show All or Hide All button above the checkboxes Figure 1 21 shows a sound window containing two views with all components hidden Show all Hide all Components 3 Line Titles Position Markers Scrollbars Selection Control Points Selection Labels Selection Table View Selection Buttons oT N N N NNN OO R aa Figure 1 20 The visibility controls for sound window components at the bottom of the side panel s Layout tab Sound 1 ChestnutSidedWarbler aif Figure 1 21 A sound window with all components hidden By default all window components are displayed except for line titles which identify the view type and number of each view Figure 1 22 If the sound has multiple channels see Working with multi channel sounds Raven 1 2 User s Manual 25 Chapter 1 Getting Started in Chapter 5 page 124 or a view has multiple lines see the next section channel and line numbers are displayed in line titles
222. sity and the Cornell Lab of Ornithology make no claims regarding the performance of these products Credits Raven was developed with partial support from the US National Science Foundation grant DBI 9876714 Principal Investigators Christopher W Clark and Kurt M Fristrup with additional support from the Cornell Lab of Ornithology Raven was written by Harold Mills Tim Krein Scott Maher Christina Ahrens Jason Rohrer and Jason Adaska The Raven User s Manual was written by Russell A Charif with contributions by Wendy Alberg Raven artwork by Diane Tessaglia Hymes The Raven development project is under the general direction of Christopher W Clark and Kurt M Fristrup Citation When citing use of Raven in scientific publications please refer to this manual as follows Charif RA CW Clark and KM Fristrup 2004 Raven 1 2 User s Manual Cornell Laboratory of Ornithology Ithaca NY For more information about Raven visit the Raven website www birds cornell edu raven Bioacoustics Research Program Cornell Lab of Ornithology 159 Sapsucker Woods Rd Ithaca NY 14850 USA Raven 1 2 User s Manual revision 1 Contents About This Manual 0 0 0 cc eee eee ix Typographical conventions 0 cc cee cece cece eee eee eee e eens 1x FOME elo cstes ene E PEE teres EERE ERAI eG RAEES a ko EEE S ix Menu Commands 2 304 0 e404 pata dathepiiaae a a Poke peeing pe ME hee ix Cross reference links
223. soid at the point where the power is 3 dB lower than the maximum power in the spectrum Figure 3 7 pe Amplitude Frequency Figure 3 7 Spectrum of a pure tone sinusoidal signal The 3 dB band width is the width BW in Hz of the main lobe of the spectrum at the point where the power is 3 dB less than the maximum power in the spectrum Raven 1 2 User s Manual Choosing the window size Chapter 3 Spectrographic Analysis When you change the window size or the window type the 3 dB Band width field is immediately updated to display the corresponding band width For a given window type improved time resolution shorter windows inevitably results in poorer frequency resolution larger band widths You can edit the 3 dB Bandwidth field to specify a desired value directly When you press lt Enter gt click on another field in the dialog or click OK or Apply Raven will choose the window size that results in the closest available approximation to the 3 dB Bandwidth value you entered For further discussion of the tradeoff between time and frequency resolu tion in spectrograms see Appendix B A Biologist s Introduction to Spec trum Analysis In a spectrogram where you are typically interested in frequency varia tions with time the best choice of window size depends in part on the nature of the signal and on what features you are most interested in observing or measuring If you are most concerned with preci
224. st 1 Contrast 2 f f C5 C4 lt rangey gt range gt Power Figure 3 13 Relationship between color and power values in a default grayscale spectrogram for two different contrast settings fi f gt c and c defined as in Figure 3 12 Increasing the contrast arrows decreases the range of power values between white floor and black ceiling When Raven initially displays a spectrogram the floor and ceiling values are set to values that yield acceptable spectrogram displays with a wide range of signal amplitudes The initial contrast and brightness settings are arbitrarily assigned values of 50 If you set contrast to 100 the floor and ceiling values are set equal to each other so that the spectrogram displays only two colors which are the floor and ceiling colors by default white and black In this case adjust ing the brightness moves the threshold between these two colors Each individual spectrum in a spectrogram has a time associated with it called the spectrum time The spectrum time is the time halfway through the block of samples from which the spectrum was calculated the spec trum source data In an unsmoothed spectrogram Raven displays each individual spectrum in a spectrogram so that its horizontal midpoint is at the spectrum time Thus in a waveform and spectrogram linked to each other by time position and scale the midpoint of each individual spec trum is aligned with the midpoint of the corresponding source
225. surement display precision for frequency mea surements uncomment and edit the following entry raven measurement basic frequency defaultValue Format 0 0000 To override the default measurement precision for frequency measure ments and specify a different precision for Low Frequency High Fre quency Delta Frequency orMax Frequency uncomment and edit the appropriate one of the following entries raven measurement basic lowFrequency default ValueFormat 0 000 raven measurement basic highFrequency default ValueFormat 0 000 raven measurement basic deltaFrequency default ValueFormat 0 000 raven measurement basic maxFregquency default ValueFormat 0 000 To specify the default measurement display precision for amplitude mea surements uncomment and edit the following entry raven measurement basic amplitude default ValueFormat 0 000 To override the default measurement precision for amplitude measure ments and specify a different precision for Min Amplitude Max Amplitude Peak Amplitude or RMS Amplitude uncomment and edit the appropriate one of the following entries raven measurement basic minAmplitude default ValueFormat 0 000 raven measurement basic maxAmplitude default ValueFormat 0 000 raven measurement basic peakAmplitude default ValueFormat 0 000 raven measurement basi
226. tacting the Raven development and support team on page 48 you need to sup ply your email address in Raven s preference file When first installed the preference file contains the line raven feedback fromAddress yourEmailAddress yourISP The string yourEmailAddress yourISP should be replaced with your complete email address That address will then be used in the From field of any email that you send from within Raven Depending on how your computer is configured you may need to supply Raven with the address of your outgoing mail server known as an SMTP Standard Mail Transfer Protocol server If you have trouble sending email feedback from within Raven remove the from the line raven feedback smtpServer and fill in the address of your SMTP server at the end of the line If you don t know the address of your SMTP server you may be able to find it in a configuration or settings dialog of your usual email program or you can obtain it from your network administrator or internet service provider Raven 1 2 User s Manual 151 Chapter 6 Preferences 152 Raven 1 2 User s Manual Appendix A Digital Representation of Sound About this appendix Digital sampling This appendix provides a brief explanation of how sound is represented digitally An understanding of the basic principles introduced here will be helpful in using Raven Before a continuous time varying signal such as sound can be m
227. tent or layout of information in windows or dialog boxes illustrations are shown from both platforms Typographical conventions Fonts Menu commands Cross reference links Boxed notes Throughout the manual an alternate font is used to identify named items in the Raven user interface such as menus menu commands and items in dialog boxes Example To delete a view activate the view and choose Delete from its contextual menu or from the View menu Menu commands are identified by the name of the menu followed by gt followed by the name of the command Example File gt Save Sound 1 Cross references within the PDF text are in blue and are hyperlinks click ing a cross reference when viewing the text in Adobe Acrobat or Adobe Acrobat Reader will take you directly to the referenced place in the text To return to the referencing point in the text click the Back button in the Acrobat toolbar Boxes like this supplement the main text by providing helpful tips or calling your attention to specific points Boxes like this provide information that is specific to WINDOWS either the Windows or Mac OS version of Raven Raven 1 2 User s Manual ix About This Manual Contextual menus This manual refers in many places to commands located on contextual menus or context menus A contextual menu is a menu that is relevant to the particular item identified by the location of the mou
228. the Selection tab in the side panel The Selection tab in the side panel displays the Begin Time End Time Delta Time Low Frequency High Frequency and Delta Frequency for the active selection Figure 4 7 All six of these fields are editable so you can adjust the selection bounds by typing values into these fields Any change that you make to one of these fields takes effect when you press lt Enter gt or lt Tab gt or when you click anywhere outside of the field that you ve changed If you change Delta Time or Delta Frequency field Raven keeps the Start Time and Low Frequency fields constant and adjusts the End Time or High Frequency as necessary Raven 1 2 User s Manual Modifying selection channels Selection tables in paged sound windows Saving the active selection Copying selected rows from the selection table Chapter 4 Selections and Measurements Selection 2 Time Begin 9 322 11 295 Delta 1 973 Frequency Hz 558 0 High 7633 5 Delta 69754 hannels End Low O LI SI LI awmu le Selection Figure 4 7 The Selection tab in the side panel This example is from a four channel sound file For multi channel signals the Selection tab also displays a list of the chan nels in the signal Figure 4 7 with checkboxes indicating the channels in which the active selection is defined To change the channels in which the acti
229. tical frequency axis New recorder button New view buttons Spectrogram brightness contrast controls Playback controls 9 Raven 1 2 g 7 o en Veyer fA Sound 1 ChestnutSidedWarbler aif i H Waveform 1 M Spectrogram 1 i 1 Lines 1 _ Time position marker View selection button Group By View 8 Channels Mi 8 Components Mi Axes Line Titles i Position Markers M Scrollbars M Selection Control Points M Selection Labels M Selection Table View Selection Buttons Figure 1 5 The Raven window on a Mac OS computer with one sound window open At the scale of magnification shown you can t see individual cycles of oscillation of the waveform what you see is the envelope of the entire sig nal Later in this chapter you ll learn how to zoom in to see fine details of a waveform As you move the mouse pointer over the waveform view the time of the pointer s location and the amplitude of the waveform at that time are shown in the mouse measurement field at the bottom of the Raven window 6 Raven 1 2 User s Manual The active view Spectrogram brightness and contrast Chapter 1 Getting Started Figure 1 4 Often the time scale is so compressed that the number of sample points represented exceeds the number of pixels in the window In this case each pixel stands for multiple sample points and the measure ment display shows the minimum and maximum va
230. ticular file in a sequence 123 Selections spanning pages uasan aaaea 123 Reconfiguring paging for an existing Window a a ssaa saaa aaua 123 Working with multi channel sounds 0 cece eee eee e eee 124 Displaying and hiding channels 0 00 e eee 124 Editing multi channel sounds 00 e eee eae 125 Selecting channels for editing operations 000020 ee eeaes 125 Correcting sounds acquired at altered speeds 00sec eeee 126 Setting the scale and position of View axes 00 c cece eee eens 128 Creating linked spectrographic views 0c cece cece cece eens 128 Filtering and amplifying sounds cc cece cece eee weenie 128 FING FING eesti Bue e e dt E a EE Maho es Pee Elie eee eee 128 AAIWAPIIT YING he eo ok al ee Nh Ee RA Oats ier Bid AON cet il ik 129 Editing color schemes sist4 situa iia tie ise tod E line EE eo 129 Choosing a color scheme element to edit 22000002000 132 Choosing Colors eae he geek eee gad eee eee bs eae eae aly 132 Swatches color CHOOSE 1 ee 132 HSB GOlOr NOOSE ti er at ead Gh aes tas Be nak bn ea 133 RGB Color CHOOSEM on pie dss ls alas ye Va ed e Ha ee ae aa eRe alee as 133 Opacity 2 224 peach aesd eas peak a Gane ated ga beeen cane ie 134 Raven 1 2 User s Manual V Color scheme presets sosh sc 4 4 ana ebb peiliwehag abun eta hades 135 Auto Apply Apply Reset OK and Close
231. time varying signals spectrograms and STFT analysis 165 Record length bandwidth and the time frequency uncertainty principle 166 Making Spectrosramss 6hsde ces deter tcars cna cesedss Meee Sea owas 168 Analysis resolution and the time frequency uncertainty principle 169 Time grid spacing and window overlap nasasa anasa aeea 171 Frequency grid spacing and DFT size 0 eee 172 Spectral smearing and sidelobes 0 cee eee 173 Window functions 0 0 0 2 eee 175 For further treading s s eae c dasy ea E seen a dew area eae ee days 177 Appendix I Configuring Audio Input 0 179 About this appendix save ieee Ghee te eee eo eee ae tee asks 179 Windows 98 2000 and XP 1 ce ccc cece ce cent eee eeeeees 179 Mac OS Xaram rae A dekh yee EYED AAAs Oe ee Oe ea 181 Raven 1 2 User s Manual vil viii Raven 1 2 User s Manual About This Manual This manual describes Raven 1 2 which runs on Windows and Mac OS X computers Raven s appearance on the two operating systems is slightly different In most cases the differences in appearance are cosmetic and simply reflect different styles used for rendering windows dialog boxes and other user interface items In cases where the differences are merely cosmetic illustrations in this manual show screen shots either from the Windows or the Mac OS version of Raven In the few cases where there are more significant differences in the con
232. tion parameters for Raven sound windows and views Presets simplify config uring windows and views by enabling you to set multiple parameters in one step For example a color scheme contains color specifications for the spectrogram color map and for fifteen other display elements such as Raven 1 2 User s Manual Spectrogram presets Recorder presets Chapter 6 Preferences point selections border and fill for range selections position markers and so on You can alter any of the predefined colors that Raven provides and then save the entire set of colors as a color scheme preset that can be retrieved later with a single mouse click The sections below briefly describe each type of preset provide cross ref erences to further discussions elsewhere in this manual and explain how to specify a preference for the default preset A spectrogram preset saves the state of all of the parameters and controls in the Configure Spectrogram dialog under a single preset name You can retrieve a saved spectrogram preset from the Preset menu within the Con figure Spectrogram dialog Spectrogram presets are discussed further in Spectrogram presets on page 88 Raven is installed with a spectrogram preset named Default which is initially specified as the default by the following entry in the preference file raven preset spectrogramParameters defaultPreset Default To change the default to a different spectrogram preset edit this ent
233. tral peak this reduction in sidelobe magnitude is termed the sidelobe rejection and is expressed in decibels Table B 1 Given a particular record length the choice of window function thus determines the sidelobe rejection and also the width of the center lobe The width of the center lobe in the spec trum of a pure tone is the filter bandwidth Table B 1 Sidelobe rejection for Raven s five window types The sidelobe rejection for each type is expressed as the height of the highest sidelobe relative to the peak of the main lobe Window type Sidelobe rejection dB Blackman 57 Hamming 41 Hann 31 Rectangular 13 Triangular 25 176 Raven 1 2 User s Manual For further reading Appendix B Spectrum Analysis The books and articles listed below can provide entry at several levels into the vast literature on spectrum analysis and digital signal processing Beecher M D 1988 Spectrographic analysis of animal vocalizations Implications of the uncertainty principle Bioacoustics 1 1 187 207 Includes a discussion of choosing an optimum filter bandwidth for the analysis of frequency modulated bioacoustic signals Bradbury J and S Vehrencamp 1998 Principles of Animal Communica tion Sinauer Associates Sunderland MA 882 pp Chapter 3 provides an excellent introduction for non specialist readers to the principles of spectrum analysis and also discusses spectral
234. trol click to select Raven 1 2 User s Manual Annotations Saving the selection table to a text file Chapter 1 Getting Started multiple non adjacent measurements When you ve finished configuring the set of measurements you want click OK The order in which measurement columns are displayed in the selection table is determined by the order in which they appear in the list of Displayed Measurement in the Measure ment Chooser 8080 Measurement Chooser Raven Preset Displayed Measurements Available Measurements Begin Time Delta Time End Time Delta Frequency Low Frequency High Frequency Peak Amplitude Peak Time Max Amplitude Max Time Min Amplitude v Figure 1 27 The Measurement Chooser dialog box In addition to the measurements provided by Raven you can define addi tional columns in the selection table to contain annotations that you enter interactively Each annotation column has a name that you define e g Song Type or Individual ID and can contain any information you want Annotations are discussed in Annotations in Chapter 4 page 99 Choose File gt Save Selection Table As to save the measurements that are visible in the selection table as a tab delimited text file for easy import into statistical spreadsheet or other programs You can also retrieve selec tion information later within Raven as described in Saving and retriev ing selectio
235. ts seconds End Time all view types The time at which the selection ends Units seconds Raven 1 2 User s Manual 111 Chapter 4 Selections and Measurements 112 High Frequency all view types The upper frequency bound of the selection Units Hz Length all view types The number of frames contained in a selection For waveform views the number of frames equals the number of samples in a single channel For spectrogram and spectrogram slice views the number of frames equals the number of individual spectra in the selection in one channel For selec tion spectrum views the number of frames always equals 1 Low Frequency all view types The lower frequency bound of the selection Units Hz Max Amplitude waveform The maximum of all of the sample values in the selection Units dimen sionless sample values See also Min Amplitude and Peak Amplitude Max Frequency spectrogram spectrogram Slice The frequency at which Max Power occurs within the selection If Max Power occurs at more than one time and or frequency the lowest fre quency at Max Time at which Max Power occurs Units Hz See also Max Power Max Time Max Power spectrogram spectrogram Slice The maximum power in the selection In a grayscale spectrogram the maximum power in a selection is the power at the darkest point in the selection Units dB re 1 dimensionless sample unit See also Max Time Max Time all view types
236. ts you specify whether the sound to be acquired is at normal speed or slowed down or sped up by a specified factor rela tive to normal speed To hide the Speed tab click the Simple button that appears in place of the Advanced button For example to shift signals from 150 kHz down so that they could be acquired by a sound card with a maximum bandwidth of 22 kHz you could play the recording at 1 8 normal speed during acquisition 150 kHz 8 18 75 kHz In this case you would specify in the Speed tab that the recording was slowed down by a factor of 8 If you provide the appropriate input speed correction factor in the Speed tab then Raven will display time and frequency axes of views and mea surements so that they refer to the original sound at normal speed Sounds that are acquired at an altered speed using the 3 appropriate speed correction factor behave in Raven as if they had been acquired at normal speed Thus to hear sounds that were originally above or below the human hear ing range you will need to specify an appropriately low or high speed for playback as described in Playback rate in Chapter 1 page 10 1 Aliasing is a type of distortion that occurs when sounds that are being digi tized contain energy at frequencies that are more than half the sampling rate Aliasing is explained more fully in Aliasing and the Nyquist frequency in Appendix A page 154 68 Raven 1 2 User s Manual Chapt
237. uences the page navigation panel displays the name of the file containing the start of the current page To move the start of the page to the beginning of a particular file choose the name of that file from the file name drop down menu You can create a selection that spans boundaries between pages by shift clicking Click once at the start or end of the interval you wish to select then page forward or back as needed and shift click at the other limit of the interval Once the selection is created you can copy or save it as you would with any selection in a non paged window You can change the page size and the page and step increments for a paged sound window at any time by choosing Configure Paging from the contextual menu for the page navigation panel You can then enter Raven 1 2 User s Manual 123 Chapter 5 Advanced Raven Usage new values for any of the page configuration parameters in the Configure Paging dialog box Figure 5 6 808 Configure Paging Page size 30 seconds HA Page increment 90 percent 4 Step increment 10 percent H Figure 5 6 The Configure Paging dialog box which is used to recon figure paging for an existing paged sound window Working with multi channel sounds Raven allows you to work with sounds containing any number of chan nels The sound cards supplied with most computers allow you to record and play back sounds containing either one or two channels i e mono or stereo
238. uncheck or check the box next to the name of that view Raven 1 2 User s Manual 23 Chapter 1 Getting Started Show all Hide all lV H Waveform 1 v Spectrogram 1 Lines a Group By Channels 1 RI h Layout Selection Playback Figure 1 19 The Layout tab for a sound window that contains two views The Component Visibility pane has been hidden by dragging the separator bar above it down Another way to hide a view is to activate that view and choose Hide View from the View menu or from that view s contextual menu Deleting a view To delete a view activate the view and choose Delete View from its con textual menu or from the View menu When you delete a view as opposed to hiding it the memory occupied by that view is released for reuse Re displaying a hidden view occurs instantly whereas re displaying a view that was deleted requires that it be recalculated which may take a signifi cant amount of time When you activate a contextual menu in a view pane view 3 specific commands in the menu apply to whichever view the mouse pointer is on when the menu is activated irrespective of whether or not that view is active Changing the order To rearrange the order in which views are displayed in the sound win in which views are dow you can drag and drop view names in the Layout tab displayed You can also move a view up or down within the sound window by choo
239. updates take effect the next time you start Raven WINDOWS On Windows computers after updates are successfully downloaded Raven will ask if you want to restart Raven immediately If you click Yes Raven automati cally quits and restarts itself You can disable Raven s automatic update checking by set 3 ting the value of raven updates automatic to false in the Raven preferences file as explained in Automatic updates in Chapter 6 page 151 Raven 1 2 User s Manual 141 Chapter 5 Advanced Raven Usage 142 Raven 1 2 User s Manual Chapter 6 About this chapter Preferences Customizing Raven This chapter explains how to use Raven preferences to configure many aspects of Raven s default appearance and behavior About Raven preferences The Raven preference file You can control the default appearance and behavior of many parts of Raven by setting preferences You set preferences by editing the Raven pref erence file with a text editing program or word processor Raven allows you to specify preferences for the following Default presets for spectrogram parameters recorder parameters win dow layout view color scheme and measurement list Default workspace to open when Raven is launched Default directories that Raven will use for opening and saving files Default precision for measurements displayed in the selection table Behavior of audio recorders when
240. ust also copy or move the sound files and selection table files and their parent folders that are refer enced by the workspace in order for Raven to open the work space properly Printing and exporting images 44 Printing To print the active sound window choose File gt Print Sound N or press lt Ctrl P gt Windows or lt Command P gt Mac OS then click OK in the print dialog that appears When Raven prints it sends an image of the active window directly to the printer without rescaling or resizing You may need to experiment with the horizontal and vertical size of the window to achieve the desired printed result Once you find window dimensions that yield desirable printed output you can use a window preset to save the dimensions for future use By default Raven prints in portrait orientation To change to landscape orientation choose File gt Printer Page Setup and choose Landscape ori entation in the Page Setup dialog The currently selected print orientation Raven 1 2 User s Manual Exporting images to files Copying images to the clipboard Chapter 1 Getting Started is indicated by the orientation of the page icon next to Printer Page Setup in the File menu a dialog appears that contains another set of controls for choosing page orientation These controls may not correctly display or allow you to change the actual page orientation To change the page orientatio
241. ve selection is defined check or uncheck channels as needed Paged sound windows provide a mechanism for working with sounds that are too large to fit in the memory available to Raven In a paged win dow only part of the entire sound called a page is in memory at any given moment Paged sound windows are discussed in detail in Paged sound windows opening large sounds in Chapter 5 page 120 The selection table in a paged sound window displays all of the selections in the signal irrespective of whether the selections are presently in memory with their associated measurements and annotations If you activate a selection in the table for which the audio data are not in memory the page centered around the selection is loaded replacing the current page and the active view is centered around the selection To save the audio data in the active selection to a separate file choose File gt Save Active Selection As You can copy selected rows from a window s selection table and paste the measurements into another program such as a spreadsheet word pro cessing or statistics program Raven 1 2 User s Manual 107 Chapter 4 Selections and Measurements Clearing selections To select a single row for copying click anywhere in the row To select a range of rows click on the first or last row you want then shift click on the last or first row you want To select multiple rows that are not adja cent to each other hold
242. ve view Figure 1 11 Buttons marked with and at the right and bottom ends of the horizontal and vertical scrollbars respectively increase and decrease magnification zoom in and out around the current position along that axis Raven 1 2 User s Manual Chapter 1 Getting Started VERTICAL Y Zoom in Zoom out Zoom to all Zoom to selection 6 7 DI 4 0 Zoomin Zoom to all Zoom out HORIZONTAL X Figure 1 11 The zoom controls which apply to the active view The Zoom to Selection button is gray if no selection exists in the signal Each time you click a Zoom In or Zoom Out button the corresponding axis of the active view is re scaled by a factor of 2 1 41 Thus clicking the Zoom In or Zoom Out button twice in succession changes the scale by a factor of 2 To zoom in horizontally on a view first make sure that view is active then move the horizontal position marker to the point where you want to center the zoom Click the button at the end of the horizontal scrollbar and observe how the display changes Clicking the button reverses the change Each time that you zoom in or out horizontally or vertically the corresponding scroll thumb shortens or lengthens to indi cate what proportion of the signal is visible Remember that the scroll thumb is half the length of the scrollbar when that axis s scale is set to its default value If you click the horizonta
243. w it is set to 80 134 Raven 1 2 User s Manual Chapter 5 Advanced Raven Usage Color scheme You can save the current color scheme as a color scheme preset which you presets can then apply later to any sound window without having to specify the colors of all of the elements in the color scheme individually Commands for saving and applying color scheme presets are in the color scheme Pre set menu which is accessible from the View menu from the contextual menu for any view and from within the Color Scheme Editor dialog box To save the current color scheme as a preset choose Preset gt Save As To apply an existing color scheme preset choose the name of that preset from the color scheme Preset menu When the Save Color Scheme Preset dialog box appears enter a name for the preset and click OK Color Scheme within the Raven program folder You can also create additional folders within the Color Scheme folder by clicking on the New Folder icon within the Save Color Scheme Preset dialog These folders will appear as submenus in the color scheme Preset menu with each sub menu listing the presets in the corresponding folder b Color scheme presets must be saved in the folder Presets Auto Apply Apply If the Auto apply checkbox is checked the default Raven immediately Reset OK and applies any change you make to an element s color or opacity without you Close needing to click the Apply button For parameters t
244. ween second level groups Working with more than one sound 40 Raven lets you work with more than one sound at a time When more than one sound window is open the tools in Raven s toolbar e g New View buttons brightness contrast and playback controls and in the side panel s Layout and Playback tabs always refer to the active window the one window in which the title bar is colored The side panel s Linkage tab shows views for all sounds that are open since Raven lets you link views of different sound windows to each other You can activate a sound win Raven 1 2 User s Manual Chapter 1 Getting Started dow by clicking anywhere in it with the mouse You can also activate a window by choosing its name from the Windows menu or by clicking on the name of one of its views in the side panel s Linkage tab You can paste portions of sounds copied or cut from one window into another data on the clipboard is the same as that of the destination sound If the sample rates do not match the resulting sound will probably not be what you intended It is up to you to ensure that the sampling rates match b Raven 1 2 does not check whether the sampling rate of the Using sound window presets You can save information about the layout of a sound window in a window preset which you can later apply to another sound window or to the same window A window preset includes information about the size of a
245. which a signal is acquired or saved does not affect the speed of spectrogram calculation because Raven always con verts signals to a 16 bit representation for internal operations even if the signal was initially acquired or saved with a different sample size Raven 1 2 User s Manual 159 Appendix A Digital Representation of Sound 160 Raven 1 2 User s Manual AppendixB A Biologist s Introduction to About this appendix Spectrum Analysis What sound is This appendix provides some conceptual background for making and interpreting spectrogram and spectrogram slice views with Raven It introduces the short time Fourier transform STFT the mathematical technique used by Raven for making spectrograms We do not discuss the mathematics of the STFT but instead treat it here as a black box This black box has controls on its outside that affect its operation in important ways One aim of this appendix is to convey enough qualitative under standing of the behavior of this box to allow intelligent use of its controls without delving into the box s internal mechanism Specific details of the controls are covered in Chapter 3 Spectrographic Analysis A second aim of this appendix is to explain some of the limitations and tradeoffs intrinsic to spectrum analysis of time varying signals More rigorous mathematical treatments of spectral analysis at several levels of sophisti cation can be found in the references listed at the
246. win dow what views are displayed whether or not the selection table is show ing and other properties Table 1 1 Raven 1 2 User s Manual 41 Chapter 1 Getting Started 42 Table 1 1 Window properties saved in window presets window size view types parameters color schemes positions scales sizes spectrogram parameters spectrogram brightness and contrast selection table visibility and size measurement list selection label configuration selection label visibility axis visibility line title visibility position marker visibility view selection button visibility scrollbar visibility To save a window preset first configure the properties listed in Table 1 1 the way you want to save them then choose View gt Window Preset gt Save As When the Save Sound Window Preset dialog box appears enter a name for the preset and click OK Sound Window within the Raven program folder You can also create additional folders within the Sound Window folder by clicking on the New Folder icon within the Save Sound Window dialog These folders will appear as sub menus in the Window Preset menu with each submenu list ing the presets in the corresponding folder b Window presets must be saved in the folder Presets To apply a window preset that s already been saved to the active sound window choose View gt Window Preset gt Preset name Wh
247. windows 107 collapsing 31 configuring 102 105 copying rows 107 108 expanding 31 saving 33 sort order 104 visibility and window presets 42 Raven 1 2 User s Manual Index visibility of entries 104 selections 26 27 30 32 34 activating 28 105 active 28 active selection 28 bounds 32 clearing 30 copying 34 creating 26 27 cutting 34 deactivating 30 defining 26 27 deleting data 34 ID 31 inactive 28 modifying 27 modifying bounds 106 modifying channels 107 multi channel 101 102 number 31 pasting 34 point 26 29 range 26 27 removing 30 renumbering 105 retrieving 110 saving active selection 107 spanning page boundaries 123 sequence tags in file name templates 59 short time Fourier transform STFT 166 Show All window components 25 Show All Channels 124 Show All Views 24 Show All Window Components 25 showing views 23 showing hiding channels 124 side panel 4 8 hiding 8 resizing 8 showing 8 sidelobe rejection 77 176 sidelobes 76 173 175 signal acquisition 51 See recording a signal Smooth Spectrogram View menu 93 95 SMTP Standard Mail Transfer Protocol server 151 sonagrams 165 sound files AIFF format 43 opening 1 3 opening multiple 115 116 saving 43 WAVE format 43 sound pressure 161 162 189 Index sound window 5 7 activating 40 closing 8 minimizing 8 moving 8 printing 44 resizing 8 sound win
248. ws behave like non paged windows except that you cannot perform editing operations that alter the audio data e Paste Delete Filter or Amplify When you first open a sound file or a sound file sequence Raven displays the Configure New Sound Window dialog box which gives you the choice of loading the entire sound into memory or creating a paged sound win dow Figure 5 4 To open a sound in a new paged sound window choose Page Sound To specify how much of the sound should be loaded into memory at any given time enter a value into the Page size field You can choose units of seconds or minutes for page size from the drop down menu Page increment and Step increment specify the amount by which Raven 1 2 User s Manual Navigating through signals in paged sound windows Chapter 5 Advanced Raven Usage the paged display moves when you click the Page Forward Page Back Step Forward or Step Back controls as described in Moving the page incrementally the Page and Step buttons on page 123 You can specify Page increment and Step increment either as a percent of the page size or as an absolute number of seconds or minutes by choosing the appropriate units from the drop down menu next to each field S Configure New Sound Window f x Window Speed Preset Default v Paging Open entire sound Page sound Page size 10 seconds Y Page increment 90 percent v Step increment 10 percent
249. y click and drag from one side to the other of the part of the signal you want to listen to in either the wave form or spectrogram view Raven marks your selection with a colored rectangle Click the Play button to play it The magenta vertical line at the left hand edge of the waveform view is the time axis position marker Each view in a sound window has two posi tion markers which identify unique locations along the horizontal and vertical axes Position markers are important for several types of Raven operations and are discussed further in Changing the position and scale of a view zooming on page 10 Using the mouse grab the time axis position marker in either the wave form or spectrogram view and move it slightly away from the left edge of the window Figure 1 8 Click the Scrolling Play button to play the signal In scrolling playback the signal view scrolls from right to left beneath the position marker like tape moving past the playback head of a tape recorder The position marker identifies the point in time that you are hearing Raven 1 2 User s Manual 9 Chapter 1 Getting Started Playback rate 4 Sound 1 ChestnutSidedWarbler aif Figure 1 8 The ChestnutSidedWarbler sound window shown in Figure 1 4 with the time axis position marker moved away from the left edge of the window During scrolling playback you can drag the scroll thumb to move the sig nal so that a particular point of int
250. ysis plot frequency on the vertical axis versus time on the horizontal the amplitude of a given frequency component at a given time is represented by a color by default grayscale value Figure B 4 Figure B 4 Smoothed sound spectrogram of part of a song of a chest nut sided warbler digitized at 44 1 kHz Spectrograms are produced by a procedure known as the short time Fourier transform STFT The STFT divides the entire signal into a series of succes sive short time segments called records or frames Each record is used as the input to a DFT generating a series of spectra one for each record To display a spectrogram the spectra of successive records are plotted side by side with frequency running vertically and amplitude at each fre quency represented by a color by default grayscale value Raven s spec trogram slice view displays the spectrum of one record at a time as a line graph with frequency on the horizontal axis and amplitude on the verti cal axis A spectrogram can be characterized by its DFT size expressed as the number of digitized amplitude samples that are processed to create each individual spectrum The STFT can be considered as equivalent in function to a bank of N 2 1 bandpass filters where N is the DFT size Each filter is centered at a slightly different analysis frequency The output amplitude of each filter is proportional to the amplitude of the signal in a discrete frequency band or bin cente

Raven 1.2 User`s Manual - Cornell Lab of Ornithology

Contents

Download Pdf Manuals

Related Search

Related Contents