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

Chapter 4: Amplitude Calibrationrecalibrated instantly, causing the window and the measurement panel (if it isshowing) to be redrawn to reflect the changed calibration.If you have multiple signal windows open, you can recalibrate them all atonce by selecting Paste Calibration To All from the Calibration submenu on theOptions menu.Calibrations and signal editingWhen you copy or cut part of a signal, the signal’s calibration information iscopied to the clipboard with the data. When you then paste data from theclipboard into another signal, this information is preserved. For example ifyou copy a signal having a peak intensity of 100 dB, and paste it into anothersignal, the pasted data will still have a peak of 100 dB, even if the two signalswere calibrated differently. (The pasted data may look different in thewaveform window if the drawing scale of the destination window is differentfrom that of the source window.)Although Canary will allow you to paste data between signals with differentcalibration paradigms (acoustic and electric), the amplitude of the resultingsignal would be impossible to interpret.Setting the dB reference using a spectral peakWhen making measurements of the relative spectrum levels within a signal, itis often useful to assign a particular dB value (usually 0) to a peak in aspectrum, and then measure spectrum levels relative to this peak. You canreset the dB reference value for a spectral peak by selecting part of thespectrum, and then choosing Set dB reference... from the Calibrationsubmenu on the Options menu. The dialog that appears displays the dB levelof the highest peak in the selected band of the intensity spectrum, and allowsyou to edit the value displayed. If you change the value and click OK, thereference value for dB intensity levels is re-set so that the selected peak willhave the dB intensity level that you specify.When you reset the intensity dB reference value in this way, the referencevalue for pressure dB is automatically reset to preserve the dB differencebetween the average intensity and the RMS pressure of the entire signal.Making calibrated amplitude measurementsOnce you have properly calibrated a signal (either directly using the SignalCalibration dialog or indirectly by copying and pasting a calibration fromanother signal), you can use Canary’s measurement panel to make reliableamplitude measurements from waveform, spectrogram, and spectrum viewsof the signal. For further details on measurements, see Chapters 6 and 3.Canary 1.2 User’s Manual 77