[AG-TECH] about echo cancellation equipment

[Jay Beavers]

An interesting feature of Windows XP is echo cancellation in software.

I haven't played with this yet, but it is exposed via the DirectSound 8
API.

 - jcb

-----Original Message-----
From: Robert Olson [mailto:olson at mcs.anl.gov] 
Sent: Thursday, May 03, 2001 7:23 AM
To: lujian at nlsde.buaa.edu.cn; ag-tech at mcs.anl.gov
Subject: Re: [AG-TECH] about echo cancellation equipment

I'm of two minds on this. It would be cool if the echocancellation in
the 
chips worked well -- it would make simple installations work nicely
(casual 
audio use in an office PC, for instance). However, for an AG node with 
multiple microphones it would pose a problem, since the cancellation
would 
likely suffer in a multiple microphone system. This is the difference 
between the chip-based systems and the Gentner: the Gentner does echo 
cancellation per-microphone.

Another interesting variation would be the use of multiple audio cards,
one 
per mic -- at $100 a pop for the cards, it would be less expensive. It's
a 
question of complexity vs price. The Gentner also does good things with
its 
support of the balanced audio connections, connectivity to other
devices, 
phone, etc.

Do you know if the echo cancellation options/control show up in the APIs

for programming the sound cards?

--bob

At 04:48 PM 5/3/2001 +0800, lujian wrote:
>         I heard that soundcard powered by Crystal/Cirrus SoundFusion
DSP 
> (digital signal processor) can do echo cancellation work . Is it
possible 
> that we use such a soundcard as a second choice of Gentner system?
>         And is there anyone who can tell the difference between the 
> card-based echo cancellation and Gentner echo cancellation?
>
>some reference sites:
>http://www.voyetra-turtle-beach.com/site/press/releases/santacruz090100
.asp
>http://www.cirrus.com/design/products/overview/index.cfm?ProductID=42