Speex dev - Feb 2013 - Speex and echo / ambient noise cancellation

Hello.  I'm new to Speex.  I see that noise cancellation is just one of
many features of Speex.  I'd like to learn more about this feature.

I've implemented an ios app on my iphone.  It's a call app.  The problem
is
there is a lot of ambient noise transmitted to the other caller over SIP.
 Is there a way to use Speex to cancel this echo / ambient noise in
real-time streaming audio?  What would the CPU implications be if this in
fact possible with Speex?

Thanks,
Sam
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://lists.xiph.org/pipermail/speex-dev/attachments/20130214/d9f81b25/attachment.htm