We used to do the following for prompts

1. noise gate, say at -40db with a fairly quick attack
2. normalize, or use a compressor with agc
3. trim both ends silence
4. add .25 seconds of silence on both ends (may want to skip this for numbers)
5. depending on the media, you can use eq to get rid of say everything below 300hz for gsm, etc, its a good idea to boost the highs and cut the lows at this time also for crySStal clear prompts (opposite of a de-esser)
   

this can all be automated through sox or soundforge

On 5/28/08, Michael Collins <mcollins@fcnetwork.com> wrote:
> You rock da hizzouse!
>
>
>
> ________________________________
>
> From: freeswitch-dev-bounces@lists.freeswitch.org
> [mailto:freeswitch-dev-bounces@lists.freeswitch.org] On Behalf Of Brian
> West
> Sent: Wednesday, May 28, 2008 2:51 AM
> To: freeswitch-dev@lists.freeswitch.org
> Subject: Re: [Freeswitch-dev] Normalizing sound files
>
>
>
> http://svn.freeswitch.org/svn/sounds/trunk/en/us/callie/dist.sh
>
>
> That script with sox shows how we do this.
>
>
> On May 28, 2008, at 2:36 AM, Michael Collins wrote:
>
> When you get new prompts you mentioned that you "normalize" them so that
> the sound level doesn't vary from one prompt to the next.  I have a set
> of prompts that GM Voices recorded specifically for me, but I haven't
> normalized them yet.  Could you let me know what process you use for
> this?