<jp12745@coewl.cen.uiuc.edu>jerry@terminus.us.dell.com> wrote:
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.
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600bps is not realistic. Most people can READ text faster than 600 bps (okay it's a little above average, but not if you were skimming; to give you a rough estimate, it's a little slower than reading one line per second) You just can't expect to cram all the intricacies and inflections of speech into a 600bps channel and be understood. But why sacrifice quality when you can use a 14400bps modem? They aren't all too expensive these days.
600 bps is not realistic? Voice has been gotten down to 400 to 600bps by doing some coding on the output of a LPC (pitch + gain + filter parameters) and transmitting that. The remote decodes to recover LPC parameters and uses that to synth speech. The quality is supposed to be the same as 2400 bps LPC (slightly synthetic sounding, definitely not 'toll quality').