How do I increase the volume of my audio files?


I have recorded all the prompts necessary for my IVR but only later I realized they weren’t loud enough…
Is there any simple way I can increase the volume of my audio files?

Thank you for any help!

sox is probably the easiest way of doing this in batch mode.

Note, although you can increase the level, you can’t improve the signal to noise ratio and it may degrade, marginally, due to additional quantisation noise.

If the sound quality is fine when recorded, then use this SOX synatx.

sox “$absolute_path_of_sound_files” -r 8000 -c 1 -s -w “$dir"new_”$filename"

You only need the format information if the input file is not self describing. .wav is self describing, but .slin is not. The parameters above assume one of those two formats.

If you do need the formats, they must be BEFORE the input file.

For this application, you either need the -v option, or the vol effect. See the man page, for details.