Reply by anjuman2 October 14, 20032003-10-14
--- In , "andrew_xiang" <ahgu@a...> wrote:
> Anyone implemented a system that get you 30dB of reduction for AEC?
>
> In my system, I only get 4X for voice signal. I will give it a try
> with white noise. But seems 30X is far away. But I don't expect
users
> to utter white noise when they speak.
>
> My calculation:
>
> 4X=SUM(abs(microphone))/SUM(abs(error))
>
> 4X leaves me a lot of residual.
>
> Are there other tricks in increasing the reduction?
>
> thanks
> Andrew

It depends on the excitation signal (ie how white it is), also what
adaptation algorithm are you using? How long is the echo tail of your
system? I have seen AECs in practical systems go up to 20dB for
128msec tail length, but not 30dB. We were using NLMS and the
excitation signal was speech. Hope the benchmark helps.


Reply by andrew_xiang September 12, 20032003-09-12
Anyone implemented a system that get you 30dB of reduction for AEC?

In my system, I only get 4X for voice signal. I will give it a try
with white noise. But seems 30X is far away. But I don't expect users
to utter white noise when they speak.

My calculation:

4X=SUM(abs(microphone))/SUM(abs(error))

4X leaves me a lot of residual.

Are there other tricks in increasing the reduction?

thanks
Andrew