Speech perception, production, and intelligibility improvements in vowel-pair contrasts among adults who receive cochlear implants

Abstract

This study investigates relations among speech perception, speech production, and intelligibility in postlingually deaf adults who receive cochlear implants (CI). Measures were made for seven vowel pairs that neighbor in acoustic space from eight postlingually deafened adults, pre- and postimplant. Improvements in a speaker’s production, perception, and intelligibility of a given vowel contrast tended to occur together. Subjects who produced vowel pairs with reduced contrast in the preimplant condition (measured by separation in the acoustic vowel space) and who showed improvement in their perception of these contrasts postimplant (measured with a phoneme identification test) were found to have improved production contrasts post-CI. These enhanced production contrasts were associated with enhanced intelligibility, as measured from responses of a group of normal-hearing listeners. The results support the hypothesis that the implant user’s improving speech perception contributes, at least in part, to that speaker’s improving speech production. [Work supported by the NIDCD, NIH.]