Abstract
A frequency compression technique for the hearing impaired was studied. In order to elucidate the validity of the frequency compressed speech for the hearing impaired, intelligibility test was made with simulated hearing loss for normal hearing subjects. Results showed that (1) the intelligibility was improved by the frequency compression for vowels, but for consonants, (2) the optimum frequency compression ratio varied depending on the individual hearing loss characteristics as well as on the formant and the fundamental frequencies of the input speech, (3) lowering of the fundamental frequency resulted in higher intelligibility in the frequency compressed speech, and (4) the improvement in intelligibility was observed in the particular vowels.
