An analysis of the characteristics of speech perception ability by the combined use of cochlear implant and lipreading

Abstract

In this study, test materials for evaluating speech perception ability by a combined use of cochlear implants and lipreading were first selected, taking into account various acoustical parameters such as fundamental frequency, intensity, and formant frequencies that can be transmitted through a speech signal processor in a cochlear implant, as well as supplemental speech information that can be obtained through mouth shape in lipreading. The test materials included the short versus long vowels, unvoiced versus voiced consonants. Japanese word accent and sentence intonation, and the 5 Japanese vowels, 50 monosyllables, 50 words, and 29 sentences that consisted of 100 words. Then, both the speech signal and the mouth shape for utterances of the test materials by a female speaker were recorded on videotapes and were presented to the subjects who had cochlear implants in Tokyo. The results showed that the test materials were useful for a detailed analysis of the characteristics of speech perception ability through the cochlear implants and lipreading.