An Approach to the Evaluation of Vocoded Speech
Willard F. Meeker, Caldwell P. Smith, William Richard Smith · The Journal of the Acoustical Society of America · 1960
Distortions peculiar to speech analysis-synthesis devices, such as the vocoder, introduce new problems in the determination of performance standards. Intelligibility can be determined in the laboratory, but standardized methods for the measurement of the characteristics of speech quality and talker recognition have not yet been established. The researcher or engineer has little to guide him in the inevitable compromises involved in the development and design of such devices and in the selection of optimum data rates. In an effort to provide such guidance, a survey was first made of certain potential military users. Speech samples obtained by filtering, telephone transmission, and vocoder processing were presented for judgments regarding intelligibility, speech quality, talker recognition, and adequacy for normal use. This paper presents the results of these surveys, along with data regarding intelligibility and talker recognition obtained in the laboratory. The speech samples used in the survey will serve as a basis for comparison in laboratory judgments to determine approximate boundaries for those parameters affecting the characteristics considered.