A Clinical Report on Speech Production of Cochlear Implant Users

In Brief Objective The aim was to assess articulation and speech intelligibility over time in a group of cochlear implant users implanted at 8 yr or over. The hypothesis was that the postoperative speech production performance would be greater than the preoperative performance. Design A test of intelligibility using sentences and an articulation test measuring non-imitative elicited speech were administered to 11 and 10 subjects, respectively, who were implanted with the 22-elec-trode cochlear implant. Nine subjects received both tests. Age at implantation ranged from 8 yr to 20 yr and implant use ranged from 1 yr to 4 yr 5 mo. Results For both the intelligibility and articulation tests roughly half of the subjects showed significant improvements over time and group mean postoperative performance significantly exceeded preoperative performance. Improvements occurred for front, middle, and back consonants; for stops, fricatives, and glides and for voiceless and voiced consonants. Conclusions Despite being deprived of acoustic speech information for many childhood years, roughly half of the patients assessed showed significant gains in speech intelligibility and articulation postimplantation. The lack of a control group of non-implanted patients means that we cannot separate out the influence of the implant on speech production from other influences such as training and tactile-kinaesthetic feedback. A benefit of “early” cochlear implantation appears to be enhanced speech production, but what about later implantation in individuals with longer-term auditory deprivation? We assessed longitudinal changes in speech production in older implant recipients, observing significant gains in speech production in about one-half of individuals. Interestingly, improvements in speech production were not related to the duration of implant use or to speech perception abilities. These results stress the need for further studies to determine the extent to which improvements in speech production reflect “auditory” input versus other factors, such as speech therapy.