Experiments on the “prosodic intelligibility” of low-frequency speech codes
Donald A. Allen, William J. Strong, E. Paul Palmer · The Journal of the Acoustical Society of America · 1979
We have reported previously on the intelligibility and discriminability of low-frequency speech codes for the severely hearing impaired. In recent experiments the following versions of speech and speech codes have been tested to explore how well they carry prosodic information: (1) natural speech; (2) speech severely low-pass filtered at 900 Hz; (3) a formant code consisting of three sinusoids scaled to the formant frequencies; (4) a largest harmonic code consisting of four harmonic sinusoids closest to the formants; and (5) an all harmonic code consisting of many harmonic sinusoids. Fundamental frequency and formant frequencies are scaled by different amounts in the various codes. Normal hearing subjects were asked to determine which of five versions of the sentence, “John drove to the store,” was heard. Speech and speech codes were tested for two female and two male talkers. “Prosodic intelligibility” results are presented and compared for the various talker, speech, and speech code combinations.