[Speex-dev] Problems with Speex echo canceller in 1.1.10

[wang.zhiping1 at zte.com.cn]

Eecho cancellation is used to eliminate the echo which mixed with near end 
speech, while it was occured by far end speech.
It always work like this:
Find the similar speech in near end speech and eliminate it.

In case 1:
Because the there is no echo in near end speech, and the EC module still 
works on it. So a inverse model is been calculated, and a inverse signal 
is produced. In this way , you can hear the far end speech.

In case 2:
Is the NES is produeced by FES? 
Maybe EC can not recognise the speech as human been just because it is 
similar.


If you want to check the EC, I think you should prepare a echo path model 
(you can find some typical models on G.168 ). You get a echo signal when 
the model applied on FES.

Once you want a signle talk test, you can use the echo signal as the NES.

If you want to test double talk, you can add the echo signal with another 
speech.



------------------------------


***********************************************
信息安全声明：本邮件包含信息归ZTE所有，
ZTE对该邮件拥有所有权利。请接收者注意
保密，未经发件人书面许可，不得向任何第
三方组织和个人透露本邮件所含信息的全部
或部分。以上声明仅适用于工作邮件。
Information Security  Notice：
The information contained in this mail is
solely property of  ZTE Corporation. 
This mail communication is confidential.
Recipients named above are obligated to
maintain secrecy and are not permitted to
disclose the contents of this communication
to others.
***********************************************
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20050729/471dda2d/attachment.html