[Speex-dev] VAD Questions

[Larry Gadallah]

Hello all:

I am interested in using Speex for an application that streams audio
from a (noisy) source, so I am interested in VAD and DTX operation.
However, after browsing the archives of this list, I note that a
number of people have not been satisfied with the operation of the VAD
algorithm in Speex. This leads me to a few questions:

- Is there a reference somewhere (other than the source itself) that
explains how the latest VAD algorithm works?
- Is it possible to obtain the VAD status of a Speex stream
asynchronously? The current API seems to imply that some kind of
polling is required to determine the voice/non-voice status.
- Does the VAD algorithm implement syllabic/sonorant rate detection,
as has been implemented many times in analog circuitry, and is
described in this (and other) papers?
http://people.csail.mit.edu/jrg/2005/IS05_schutte.pdf
- Over what time period is VAD done? Is it done on a frame by frame
basis or over some longer period?

Thank you,
-- 
Larry Gadallah, VE6VQ/W7                          lgadallah AT gmail DOT com
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