[Speex-dev] aec

Jason Harper jhharper1 at yahoo.com
Mon Oct 31 22:48:35 PST 2005

I have incorporated the speex echo cancellation into
my softphone project, but wasn't getting great
results.  I decided to simplify the problem, by
recording speaker and mic files and running testecho. 
I've been pretty happy with the preprocess module and
I wanted to focus on the mdf, so I commented out the
call to preprocess in testecho.
When I run testecho my output file looks almost
identicle to my mic file.  I don't see any reduction
in the power level of the echo.  I've looked through
some of the previous posts to this group and have
tried the obvious, such as increasing my filter length
and reversing the order of the files passed into the
Looking at the files in Audacity, the echo lags by
about 180ms.  I have experimented with filter lengths
up to 2 seconds.
I'm open to suggestions.  If anyone would like to try
my test files you can download them from:
These files are all 16-bit PCM, Little-endian.


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