[Asterisk-Users] Asterisk sound files, audio bandwidth, and sound quality

[Stephen Bosch]

Steve Underwood wrote:
> For speech, signed 16 bit linear offers no significant benefit over
> a-law or u-law. The hardware on the TDM400 card doesn't really support
> sampling rates above 8000/second, and phones are limited to that
> bandwidth anyway. If you want higher quality for some purpose, normal
> analogue phone lines are the wrong place to be looking.

Are you (or anyone else) familiar with the Octel voicemail system?
Compare the sound quality of the prompts and recorded voicemail on Octel
to Asterisk. The difference is definitely audible and distracting - and
that's even through a phone.

Perhaps they are doing something differently? I wonder if it's the
resolution or the gain that makes the difference. When I listen to the
.gsm files provided with Asterisk, there's noise when the person speaks.

-Stephen-