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Re: [codec] Thresholds and delay.

Ben Schwartz <bmschwar@fas.harvard.edu> Wed, 12 May 2010 12:28 UTC

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From: Ben Schwartz <bmschwar@fas.harvard.edu>
To: jari.hagqvist@nokia.com
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Cc: codec@ietf.org, stephen.botzko@gmail.com
Subject: Re: [codec] Thresholds and delay.
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On Wed, 2010-05-12 at 10:01 +0200, jari.hagqvist@nokia.com wrote:
> 
> Generally I believe that AECs mainly take care of the acoustic echo
> generated in the phone itself (operating on the microphone signal,
> acoustic delay up to a few ms). Do you mean that there is additional
> processing on the receiving side for the echo returning from the B
> user side?

Only in the user's head.  The psychoacoustics of echo are very different
depending on the echo time.  This means that the perceived echo-canceler
fidelity depends on the acoustic round-trip delay.  It also means that
the AEC should be retuned depending on the round-trip delay.

--Ben

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