Spectrogram Controls

The spectrogram tab of the control panel contains the following controls used to adjust the spectrograms produced by Song Scope.

For more information, please see Signal Processing Basics.

FFT Size: The FFT size control adjusts the window size (in samples) of the Fast Fourier Transform algorithm used to produce spectrograms.
FFT Overlap: The FFT overlap control adjusts the amount of overlap between FFT windows.
Frequency Minimum: The frequency minimum control adjusts the lowest frequency displayed on the spectrogram and used in comparing vocalizations. The value indicates the lowest FFT bin number.
Frequency Range: The frequency range control adjusts the range of frequencies (as measured from the minimum frequency specified above) displayed on the spectrogram and used in comparing vocalizations. The value indicates the number of FFT bins (up to the maximum).
Amplitude Gain: The amplitude gain control amplifies the input signal on both the spectrogram and waveform plot. This can also be used to adjust the volume during playback through the computer's sound hardware.
Background Filter: The background filter reduces background noise. The algorithm requires an estimate of the background power spectrum. The background filter control can be used to disable the filter, or to specify the number of seconds over which to average background noise levels to be used for the background power spectrum estimate.