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<p class=MsoNormal><span lang=EN-US>Hello.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>I have the following situation. AEC is used
in network chat software <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>over DirectSound API. Echo and reference
signals are almost aligned <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>(delay is no more than 30ms). When echo is
emulated in notebook <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>(built-in speakers + mic) everything goes
fine and echo is cancelled. <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>But when configuration includes stand-alone
speakers and mic no echo is <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>removed. Audio is in 22050 hz at 16 bit
mono format, number of samples <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>to process were 441 and tail was used 4096.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Dumps are here: <a
href="http://rapidshare.com/files/317389207/speex_AEC_test.rar.html">http://rapidshare.com/files/317389207/speex_AEC_test.rar.html</a><o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>nb_*** - working configuration (notebook)<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>sa_*** - standalone speakers with no echo
removed<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Can it be because of differences in fixed
and arbitrary acoustic systems?<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>I will appreciate any of your advises or
thoughts.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Thanks!<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Anton A. Shpakovsky<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Multimedia Software Developer<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
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