From: jerry@terminus.dell.com (Jeremy Porter)
Date: Fri, 10 Dec 93 13:09:36 PST
To: cypherpunks@toad.com
Subject: LPC for speech (fwd)
Message-ID: <9312102107.AA00551@terminus.us.dell.com>
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From jp12745@coewl.cen.uiuc.edu Fri Dec 10 14:46:07 1993
From: Jeffrey Wayne Porter <jp12745@coewl.cen.uiuc.edu>
Message-Id: <199312102045.AA16812@eehpx21.cen.uiuc.edu>
Subject: LPC for speech
To: jerry@terminus.dell.com (Jeremy Porter)
Date: Fri, 10 Dec 1993 14:45:49 -0600 (CST)
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Did you know that using LPC (linear predictive coding) on speech can
near-telephone quality at only 8 k BITs/second?  With a signficant
decrease in quality (but still very understandable... probably better
than radio) you can get the rate down to 2kbps.  If you don't mind
sounding like a speak&spell, you can go to 600bps or less.


Using LPC, you could send real-time voice over the
internet.  It would even work (maybe just barely) over a SLIP
connection.  According to my professor, LPC can be implemented
in a simple DSP chip, so I figure a 486 ought to be able to
handle it, too.  Sound like an interesting (granted maybe not
too useful) project?  It would be a way of providing secure
voice communications -- LPC code the speech, encrypt the data
stream, transmit via v.32bis modem, etc.
-- 
--------------------------------------------------------------------
Jeff Porter
jporter@uiuc.edu    TA: ECE 290..."ph Jeff Porter" for office hours


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