Newsgroups: comp.speech
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From: stephan@artn (Stephan Meyers)
Subject: REPOSE: LPC questions/idea
Message-ID: <1994Feb7.210232.17709@iitmax.iit.edu>
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Date: Mon, 7 Feb 94 21:02:32 GMT
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	I posted this a week or so ago, and haven't got any responses.
	No one here knows anything about Linear Predictive Coding?  How odd!
	I just thought I'd repost it to give it another chance.

Stephan Meyers (stephan@artn) wrote:
: 	Hi, I have some questions that should be pretty naive by the standards
: of this group.  If this material is in the FAQ, I would appreciate a pointer
: to it.
: 	I'm going to phrase my question as a series of half remembered data
: points:

: * One of my first computers was a TI-99, noted for having a speech synthesizer
: as a peripheral.  If I remember rightly how this thing worked, it used LPC to
: model the human vocal tract.  Tapes of the original speaker were analyzed to
: calculate the appropriate vocal tract parameters (tongue position, etc), which
: turns into a very tiny amount of data.  The speech synthesizer chip would then
: run this data through it's simplified vocal tract model.  Some of the speech
: was astoundingly good.
: * At the time, the computer used to do the encoding was a fairly hefty one -
: what would that break down to in today's standards?  A pentium?  An indigo?
: A connection machine?  My intuition is an indigo would be about equivalent, but
: I don't know how fast the computation was then.

: OK, enough brain dumping, you can probably see which way this is going.

: 	Would it be possible to (a) implement the LPC encoding on a common
: workstation (Let's use an indigo R4000, 100 Mhz, since that's what I've got)
: (b) run it in real time or near real time (c) is the data produced small enough
: to run through a medium speed network link in real time or near real time?
: (d) can the decoding run fast enough on the aforementioned machine, or did the
: TI chip use some goofy analog thing that wouldn't work fast enough digitally?
: (e) does TI own some sort of patent which would prevent an implementation
: without licensing?  (if so, it should be up soon, patents last 17 years, which
: would be 1976, and speak & spell came out not long after then) (f) has someone
: already done this, or parts of it?

: 	If it runs in real time, this would seem ideal for an internet voice
: chat program.  Yeah, I know phones are easier and cheaper, but it would be fun
: and perhaps there are other things you could do with it that you couldn't do
: with a phone (maybe link into network games like netrek or something).  Without
: the network, this would be good for verbal note taking - remove the computer,
: put the encoding and decoding in hardware, and you've got a nice little
: ram-based dictation box (though I suspect LPC is very susceptible to background
: noise.)

: 	If the decoding works in real time and the encoding doesn't, it would
: be handy for games.

: 	If neither end runs in real time, there would still be applications,
: such as distribution of internet broadcast radio, or speech in Mosaic.

: 	I know this technology has been in consumer applications for 10-15
: years, it should be a lot easier to pull off now.

: 	Again, please forgive me if this is in a FAQ or if I've got some of the
: information wrong - computer speech is not my field, but it seems everybody's
: all hot on speech _recognition_, and seems to consider synthesis a boring, 
: mostly solved problem.

: 		- Stephan

: --
: Stephan Meyers | stephan@artn.iit.edu
: (Art)^n Laboratories, inventors of the PHSCologram (R)
: GO(CS) d--- p---(+) c++++ !l u++ e++ m+++/--- 
: 	s--(+) n* h--- f++ g+ w+++ t++@ r x*

--
--
Stephan Meyers | stephan@artn.iit.edu
(Art)^n Laboratories, inventors of the PHSCologram (R)
GO(CS) d--- p---(+) c++++ !l u++ e++ m+++/--- 
	s--(+) n* h--- f++ g+ w+++ t++@ r x*
