Sound: Scale peak...

A command available in the Modify menu when you select one or more Sound objects. With this command you multiply the amplitude of each Sound in such a way that its absolute peak becomes the new absolute peak that you specify (see Settings).

Settings

New absolute peak
the new absolute peak of the Sound. The standard value is 0.99: this maximizes the audibility of the Sound (sounds with lower amplitude are weaker) without distorting it (sounds with absolute peaks above 1 are clipped when they are played).

Examples

The absolute peak of the following sound is 0.033:

This sound will play rather weakly. To make it louder, you can do Scale peak... with a new absolute peak of 0.99. Praat will then multiply the waveform by 30, changing the sound to the following:

The absolute peak is now 0.99, and the sound will play loudly.

The reverse is also possible. The absolute peak of the following sound is 19.8:

This sound will not play correctly: all samples with an amplitude outside the [-1;+1] range will be clipped to -1 or +1. To make this sound nicer to play, you can again do Scale peak... with a new absolute peak of 0.99. Praat will then divide the waveform by 20, changing the sound to the following:

The absolute peak is now 0.99, and the sound will play without distortion.

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© ppgb, March 28, 2010