[Asterisk-Users] most common VOIP echo simulaton for research purposes ?

[Robert Rozman]

Hi,

I'm speech recognition researcher and would like to do some research on 
recognition robustness in echo distortion of speech signal. Since VOIP is 
becoming wide spread, I'd like to simulate (one or more) common echo 
distortions that mostly appear in voip communications ? Any example, FIR or 
IIR filter or acoustical system response ?

Any other distortion worth researching ?

Thanks in advance,

regards,

Rob.