User's Manual - Cornell Lab of Ornithology - Cornell University

Chapter 1: Getting StartedClicking on the vertical squeeze button compresses the vertical dimension ofthe active pane by a factor of two, reversing the effect of the previous verticalstretch. If you activate the waveform pane, and click on the vertical stretch orsqueeze buttons, the waveform display will be redrawn as appropriate,without any change to the spectrogram pane.Click on the horizontal stretch button, and notice that the displays in both thewaveform and spectrogram panes are stretched, irrespective of which is theactive pane. A general rule in Canary is that changing the scale of eitherdimension of a pane also affects any other pane that shares that dimension.Since the waveform and the spectrogram share the time dimension, anychange to the time scale of either pane affects both panes.You can stretch or squeeze the display as many times as you want. Figure 1.6shows the signal window after it has been stretched seven times (since eachstretch is by a factor of two, the scale has thus been stretched by a factor of 2 7= 128). At this magnification, individual cycles of the waveform are visible.Compare the time axes in Figures 1.6 and 1.5; you can see that the segmentshown in Figure 1.6 is in the second syllable of the song. (If you try zoomingin on a single syllable by successively stretching the time axis in this way, youmay need to use the horizontal scroll bar to get to the part of the song shownin Figure 1.6.) If you keep zooming in on shorter and shorter segments of thesignal, eventually you will see discrete points plotted along the waveform;these are the individual digital samples of which the digitized signal iscomprised (see Appendix A for more on digital sampling).Figure 1.6. Part of a single syllable of the meadowlark song shown Figure1.5, after seven successive horizontal stretches.16 Canary 1.2 User’s Manual