Accession Number : AD0801360

Title :   SPEECH BANDWIDTH REDUCTION.

Descriptive Note : Final technical rept. Mar 65-Jun 66,

Corporate Author : PHILCO BLUE BELL PA ADVANCED COMMUNICATIONS LAB

Personal Author(s) : Jurenko, David M. ; Abt, Richard ; Schultz, John P.

Report Date : SEP 1966

Pagination or Media Count : 170

Abstract : This report presents experimental results, comclusions, and recommendations resulting from research - conducted on a speech bandwidth reduction technique based on an electrical analog of the human hearing mechanism. This research centered around the Single Equivalent Formant (SEF) technique whereby it is hypothesized that intelligent speech could be transmitted with three parameters: SEF frequency, amplitude, and pitch. This was partially proven in that the intelligence (RT word score) was measured at 75 percent for experienced speakers and listeners. However, the machine-like quality of the synthesized speech proved to negate the system's use with all but highly trained operators. Three other systems, including resynthesizing three formant speech from the SEF parameter using storage, were investigated. The system that was finally decided upon as the closest to meeting the goals is a two formant, three amplitude, and pitch system with 120 Hz bandwidth. This system has a measured RT score of 85 percent and the quality is adjudged to be quite human-like. Transmission of the parameters is accomplished.

Descriptors :   *SPEECH TRANSMISSION), (*SPEECH COMPRESSION, (*SPEECH RECOGNITION, SPEECH COMPRESSION), SOUND PITCH, BANDWIDTH, SYNTHESIS, PULSE AMPLITUDE MODULATION, SYNCHRONIZATION(ELECTRONICS), DISTORTION, MULTIPLEXING, DATA STORAGE SYSTEMS, COMPARATORS, FREQUENCY, PITCH DISCRIMINATION, INTELLIGIBILITY, AUDITORY ACUITY.

Subject Categories : Voice Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE