Re: Implementing NLMS for Echo cancelation in Speech

Hi

I am trying to write an acoustic/line echo canceller.
I choose the quite well known nlms algo.
First I tried to implent it in matlab.
When I checked the algo with any "test input" like sin wave, zigsaw etc,
I did get convergance.
Then I tried it with speech, but failed.
I tried to improve it by implementing anti-correlation filter (
Pre-whitening). I did saw minimal improvments in the filter taps, and in
terms of math output, there is error reduction ( not much). Still, when
you play the speech, you dont hear a difference.
I also implemented filter which cut all 0-100Hz fully, 100-300Hz
transition., still no change.

I recoreded the speech in a microphone with 48Khz, then downsapmled it
propely to 8K Hz (phone). It sound OK. then I added an echo by using
GoldWave/Audacity. I implemeted a -6db echo with delay of 50ms and used
400+ Taps. The format is Wav lossless.

My qustion is: I feel that I miss something. Since I didnt work with
audio
before, it could be that I fail in something very fundamental...
( I worked with lsf algos ).
I will be gratfull for any help/suggestions...
Thanks, Ilan





Thank You, But I solved the Problem. Ilan

.

Relevant Pages

  • Re: Implementing NLMS for Echo cancelation in Speech
    ... I am trying to write an acoustic/line echo canceller. ... I choose the quite well known nlms algo. ... Then I tried it with speech, ... I tried to improve it by implementing anti-correlation filter ( ...
    (comp.dsp)
  • Implementing NLMS for Echo cancelation in Speech
    ... I am trying to write an acoustic/line echo canceller. ... I choose the quite well known nlms algo. ... Then I tried it with speech, ... I tried to improve it by implementing anti-correlation filter ( ...
    (comp.dsp)
  • Re: Implementing NLMS for Echo cancelation in Speech
    ... I am trying to write an acoustic/line echo canceller. ... I choose the quite well known nlms algo. ... Then I tried it with speech, ... I tried to improve it by implementing anti-correlation filter ( ...
    (comp.dsp)
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