[TriLUG] automated Audio processing in Linux

[Brian A. Henning]

My two cents:
  What you're talking about is VOX.  Many cheap tape recorders (remember
tape?...heh), especially microcassette, will have such a feature.  It
listens all the time, and when the sound pressure (level, essentially) rises
above a certain threshold, the recorder starts rolling.  Then when the level
falls below the threshold for a length of time, the tape stops rolling (The
delay is along the lines of Marty's hysteresis suggestion, although
hysteresis technically would mean the 'stop' threshold is set lower than the
'start' threshold).  At any rate, it's (in its simplest form) not nearly so
complex as detecting a *kind* of sound; merely the *level.*  This would
still work in real-time, rather than post-processing.
  Some brief googling turned up a couple VOX programs for Windows (despite
including linux in the search terms)...  I wish I had a link to hand out,
but alas..  Anyhow, your google skills may exceed mine, so perhaps my input
will at least suggest another search angle.  If not, then maybe I've helped
educate someone else who's been reading along.

Cheers,
~B