Accession Number : AD0413461

Title :   07

Descriptive Note : Final rept.,

Corporate Author : NORTHEASTERN UNIV BOSTON MASS

Personal Author(s) : Dolansky,L. ; Barrs,J.T. ; Howard,C.R. ; Karis,C.

Report Date : 15 MAR 1963

Pagination or Media Count : 61

Abstract : Speech signals processed by a Vocoder and the digital voice data processing system have been compared with clear-speech signals by means of intelligibility tests; the quantitative intellig ibility degradation was measured under various conditions of Vocoder voicing, using varying numbers of quantizing levels for the reproduced signals. It was found that (a) the major de crease of intelligibility was attributable to the Vocoder processing; (b) the reduction of the num ber of quantizing levels had some effect upon listener confidence, but no noticeable effect upon intelligibility; (c) erroneous voiced re sponses to unvoiced sounds, processed by the Vocoder, could be eliminated in many cases by a suppression of the fricative-vowel transition region and (d) the elimination of the beginning part of initial voiceless fricatives in clear speech resulted in responses corresponding to other consonants, most frequently to voiced stops. (Author)

Descriptors :   (*SPEECH REPRESENTATION, DIGITAL), (*SPEECH RECOGNITION, INTELLIGI), (*SPEECH COMPRESSION, CODING), (*VOICE, SPEECH COMPRESSION), DATA PROCESSING, TEST METHODS, PATTERN, SPEECH.

Distribution Statement : APPROVED FOR PUBLIC RELEASE