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Article #1092Re: US Gov. sends real-time audio at 2400 baud!
From: Pierre Racz
Date: Fri, 09 Nov 1990 18:32
Date: Fri, 09 Nov 1990 18:32
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It is possible to send intelligible voice at bit rates as low as 1k However the quality suffers. Speech quality can fall in one of the following classes: 1 - Broadcast 2 - Toll 3 - Communication 4 - Synthetic Currently, broadcast quality requires 64kbps and is your typical AM radio station quality. Toll quality is the standard telephone fare. By complex coding the bit rate can be reduced to about 10k bps. Communication quality is highly intelligible but has noticeable distortions, your would expect this from short wave radio. This level can be achieved with 4.8kbps. Synthetic quality, while 80% to 90% of the speech is intelligible, sounds "machine like", "buzzy" and the identity of the speaker cannot be recognized any more. Code rates of less than 4.8kbps (and as low as 1kbps) can be achieved at this level of quality. As time goes on, these bit rates will be reduced further.
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<1990Nov9.183212.1441@larry.mcrcim.mcgill.edu>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!uakari.primate.wisc.edu!uflorida!gatech!bloom-beacon!mcgill-vision!mcgill-vision!jeanShow Full Headers
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!uakari.primate.wisc.edu!uflorida!gatech!bloom-beacon!mcgill-vision!mcgill-vision!jean From: jean@mcgill-vision.uucp (Pierre Racz) Newsgroups: comp.dsp Subject: Re: US Gov. sends real-time audio at 2400 baud! Keywords: Low bitrate speech coding Message-ID: <1990Nov9.183212.1441@larry.mcrcim.mcgill.edu> Date: 9 Nov 90 18:32:12 GMT Sender: news@larry.mcrcim.mcgill.edu (Usenet File Owner) Distribution: na Organization: McGill University, McRCIM Lines: 20