[Speex-dev] About Sampling Rate Correction in acoustic echo

Steve Underwood steveu at coppice.org
Thu Feb 10 05:14:25 PST 2011

On 02/10/2011 06:21 PM, Andreas Engel wrote:
> I can only evaluate this with my subjective point of view. I had a 
> special test scenario doing chat with cheap webcam microphones and 
> loudspeakers. Fraunhofers solution was the only one that could 
> eliminate the echo. In double talk the quality gets lower but is still 
> very good. You might want to ask Fraunhofer for a demo version to test 
> for yourself.
> I have no details on the algorithms being used, I only know that it is 
> patented. Since it is a commercial product I doubt they are willing to 
> share any more details than they already do in that paper. But the 
> algorithm is obviously very insensitive to frequency drift.
If they charge a lot, the software will almost certainly make use of 
some interesting patented techniques. Echo cancellation is a patent 
minefield. A patent search with "Fraunhofer" might drag up something 


More information about the Speex-dev mailing list