Newsgroups: comp.dsp
Path: utzoo!utgpu!cunews!wilf
From: wilf@sce.carleton.ca (Wilf Leblanc)
Subject: Re: 300 Baud Speech Vocoding...
Message-ID: <wilf.658724742@rigel.sce.carleton.ca>
Sender: news@ccs.carleton.ca (news)
Organization: Carleton University, Ottawa, Canada
References: <1990Nov15.231800.119@xn.ll.mit.edu>
Date: 16 Nov 90 03:05:42 GMT

tj@xn.ll.mit.edu (Thomas E. Jones) writes:

>I'm a little surprised no one has talked about the low data-rate
>speech vocoding algorithms that have been developed.

Me too. I thought with all the net bandwidth regarding compression
to 'walkman' quality, someone would have brought this up.  Maybe
not walkman quality, but at least it is 'intelligable' (at a
very low data rate).

>[stuff deleted regarding segment vocoder @ 300 bps]

There is alot of literature regarding 'vocoders' at 300 (or so) bps.
Basically, most of them are an LPC vocoder (LPC10 type) with
Vector Quantization of the LPC parameters and so on.  See ICASSP
around 1980-1984.  Not (as) much written on it since then (to my
knowledge).

>A new vocoding algorithm known as Sinusoidal Coding has been
>developed by the same group at Lincoln Lab., and offers much better voice
>quality than LPC.

Hmmmmm.  Correct me if I'm wrong, but I thought Sinusoidal (Transform)
coding was a (relatively) old technique which is becoming more popular
due (mostly, if not entirely) to the work of McAuley and Quateri (my
apologies if their names are spelled wrong, but this is on memory).


>[.....]

>				- tj@xn.ll.mit.edu
>-- 
>tj@xn.ll.mit.edu or tj@ll-xn.arpa          (one of these should work)
>Thomas E. Jones, home (617) 924-8326 work (617) 981-5093

--
---
Wilf LeBlanc                                Systems and Computer Eng.
Internet: wilf@sce.carleton.ca              Carleton University
    UUCP: ...!uunet!mitel!sce!wilf          Ottawa, Ont, Canada
