Accession Number : AD0283122

Title :   THE MASKING OF SPEECH BY HIGH- AND LOW-PASS NOISE

Corporate Author : ROME AIR DEVELOPMENT CENTER GRIFFISS AFB N Y

Personal Author(s) : DYER,WILLIAM R.

Report Date : JUL 1962

Pagination or Media Count : 1

Abstract : The increased requirements in the field of military voice communications has resulted in a greater need for information on noise interference. This is especially true in the light of current emphasis on systems integration, wherein communications play such an important role. Efforts were made to determine the influence on speech communications of various forms of interference commonly encountered in sophisticated electromagnetic communications systems. A study on the masking of speech with shaped random noise is described. Harvard phonetically-balanced word lists were mixed with noise at five intensity levels and 11 frequency cutoff limits. Five well-trained subjects listened in isolation to the composite signal presented over headphones. Data are presented in both tabular and graphic form, showing the intelligibility remaining under each masking condition. Both high-pass and low-pass noise conditions resulted in complete masking at the lowest signal-to-noise ratio. An amplitude-related shift in the crossover points for the high- and low-pass masking functions was noted and is attributed to a downward spread of masking effect. (Author)

Descriptors :   *AIR FORCE COMMUNICATIONS, *COMMUNICATION AND RADIO SYSTEMS, *SPEECH TRANSMISSION, *VOICE COMMUNICATIONS, INTELLIGIBILITY, INTERFERENCE, NOISE, SIGNAL-TO-NOISE RATIC, SPEECH, TESTS

Distribution Statement : APPROVED FOR PUBLIC RELEASE