Word Intelligibility of Speech Processed by Time Division Multiplexing/PCM Communication System

摘要

During the development of the US Army's PCM multiplex equipment, testing was accomplished on a back-to-back basis. Questions arose as to the telephone circuit quality of various system configurations for equipment deployed in the field or located in the laboratory. The Fairbanks Rhyme Test was used to determine the telephone circuit quality in percent intelligibility and thus a basis was provided to compare the systems. In addition, quantitative electrical measurements of signal-to-quantizing-noise ratio, signal-to-noise ratio and output level were made on the various system configurations to determine system performance. The laboratory system provided slightly higher quality speech intelligibility than the field-deployed system. Based on the results, however, field systems can be simulated in the laboratory to determine performance in the field. (Author)