Convention Paper
Improved Vocoders
AES Convention 16 · Paper 327 · October 1964
Abstract
In the past two years channel vocoder technology has advanced to the point where intelligibility is no longer the most important factor in determining the usefulness of the channel vocoder as a communications device. There exist today several vocoders which provide word intelligibility in the 85-95% bracket at 2400 B/S. In terms of connected text or conversation such individual word intelligibility corresponds to virtually 100% understandibility. The purpose of this paper is to discuss the quality-intelligibility aspects of vocoded speech and to generally outline some areas of improvement in the channel vocoder. The term quality is a very nebulous one as we all know. In all discussion, the use of the word quality will be intimately tied to the acceptability and preference indicated by an ordinary listener.
