On Mon, Oct 22, 2012 at 10:30 AM, Michael Collins <msc@freeswitch.org> wrote:
The files we get from GMVoices are slightly "loud" for some folks, so we run them through sox with the -v 0.2 arg and it "normalizes" them a bit. However, I wouldn't do that same trick again on the sounds files in files.freeswitch.org since they've already been normalized. If you do then you'd definitely be lowering the volume to what many would consider to be a really low level.
FWIW, I seem to recall using this switch for normalising audio: sox --norm 'Automatically invoke the gain effect to guard against clipping and to normalise the audio.' However, it has been a while since trying and I usually fumble abound with sox args for a while before getting it right. Best, Gabe