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:

`Create Sound from formula: "033", 1, 0.0, 0.1, 10000,
` `... ~ -0.02 * (sin (2 * pi * 205 * x) + sin (2 * pi * 5 * x)) + 0.007
` `Draw: 0, 0, -0.033, 0.0247, "yes", "curve"
`

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:

`Scale peak: 0.99
` `Draw: 0, 0, -0.99, 0.741, "yes", "curve"
`

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:

`Create Sound from formula: "198", 1, 0.0, 0.1, 10000,
` `... ~ 12 * (sin (2 * pi * 305 * x) + sin (2 * pi * 5 * x)) - 4.2
` `Draw: 0, 0, -15.28, 19.8, "yes", "curve"
`

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:

`Scale peak: 0.99
` `Draw: 0, 0, -0.764, 0.99, "yes", "curve"
`

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

### Links to this page

- Sound files 1.2. Quantization
- Sound: Autocorrelate...
- Sounds: Convolve...
- Sounds: Cross-correlate...