[Asterisk-Users] Voice detection

[Brad Waite]

Does anyone know if there's public voice detection algorithms available?  I've 
scoured the net for the last hour or so, and I can't come up with anything 
except a few proprietary or embedded solutions.

I know dsp.c uses goertzel algorithms for DTMF detection, but how does one 
detect voice?

I dunno, maybe detecting voice isn't the way to go.  I want to begin playback of 
a file after a phone/answering machine has answered.

Suggestions?

Brad Waite