multiple .wav files, different playback volumes

I have about 250 .wav audio files which have different volumes during playback. I assume this difference is a result of moving the microphone during recordings.

Is there a way of altering the soundfile itself so that all of the files play at a similar volume.

Thanks

Answer 1

[Steven Van Vaerenbergh]

You should normalize the sounds so they have the same overall power (per time step).

For example, normalize to power 1 (per sample):

x = audioread(filename);
x = x/sqrt(mean(x.^2));

When you play the normalized sounds through the sound(), each sound should appear to have a similar volume.

In order to avoid distortions you may normalize to a smaller power though, e.g.

x = x/sqrt(mean(x.^2))/10;

If you want something more sophisticated you may have a look at dynamic range compression, though this kind of technique will modify the waveform unrecoverably.