Sound: To Intensity...

A command to create an Intensity object from every selected Sound.

Settings

Minimum pitch (Hz)
the minimum periodicity frequency in your signal. If you set it too high, you will end up with a pitch-synchronous intensity modulation. If you set it too low, your intensity contour may appear smeared, so you should set it as high as allowed by the signal if you want a sharp contour.
Time step (s)
the time step of the resulting intensity contour. If you set it to zero, the time step is computed as one quarter of the effective window length, i.e. as 0.8 / (minimum_pitch).
Subtract mean
See Intro 6.2. Configuring the intensity contour.

Algorithm

The values in the sound are first squared, then convolved with a Gaussian analysis window (Kaiser-20; sidelobes below -190 dB). The effective duration of this analysis window is 3.2 / (minimum_pitch), which will guarantee that a periodic signal is analysed as having a pitch-synchronous intensity ripple not greater than 0.00001 dB.

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© ppgb, June 5, 2010