[Speex-dev] AEC Patented ?

Jean-Christophe.Berge at etu.enseeiht.fr Jean-Christophe.Berge at etu.enseeiht.fr
Tue Oct 3 07:53:39 PDT 2006

Hello Jean-Marc Valin and all the Speex-dev team,

Today I have a little question about patents and the AEC.

I' am not a lawyer, but after a deep research in esp at cenet.com,
I found that in August 2003, an AEC called "Double talk insensitive NLMS
algorithm" (DNLMS) have been patented by Gary Q Jin, Gordon J Reesor, and
others (US 6.608.897 B1).

It uses a continuous adaptation step as speex, to avoid adaptatif filter
divergence during double-talk.

Is the computation method really the same as speex AEC (hope not) ?
Somebody who have a deep understanding of Speex AEC algorithm might have a
look at this patent ?

Thank you in advance for your answer,


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