A COMPARISON OF VOWEL PRODUCTION BY CHILDREN WITH MULTICHANNEL COCHLEAR IMPLANTS OR TACTILE AIDS - PERCEPTUAL EVIDENCE

Objective: To examine changes in perceived vowel production accuracy o ver time in prelingually deafened children who use a multichannel coch lear implant (Nucleus 22 channel) or a multichannel tactile aid (Tacta id 7) and to compare the levels of perceived vowel production accuracy attained by the two device groups. Design: The subjects were particip ants in longitudinal studies of the effects of sensory aids on the dev elopment of perceptual, speech, and language skills. As part of these studies, imitative vowel productions were elicited and transcribed bef ore each child received their sensory aid and at 6 mo intervals therea fter. Data for the current study was obtained from the predevice inter val and a later interval (postdevice) that was an average of 1.8 yr af ter the subjects received their respective devices. The subjects' vowe l productions were judged for accuracy in matching an imitative model and for correctness of vowel features (height and place). Within-group analyses were completed to determine if vowel production scores impro ved over the course of the study for each device group. Between group comparisons were performed to examine differences in mean scores at ea ch interval. Results: Before receiving their multichannel devices, the two groups of subjects demonstrated similar imitative vowel productio n skills. After an average of 1.8 yr of device use, the cochlear impla nt subjects demonstrated significantly improved production of diphthon gs and all vowel categories except low vowels. The Tactaid 7 subjects demonstrated significant improvement only in the production of diphtho ngs. Thus, cochlear implant recipients' vowel production skills were f ound to be significantly better than those of the Tactaid 7 users afte r a comparable amount of device experience. Conclusions: The vowel pro duction gains of the cochlear implant subjects were similar in amount to those noted in other studies of children who use the Nucleus multic hannel cochlear implant and further confirm the potential of this devi ce for improved speech production in prelingually deafened children. T he differences between the performance of the two groups demonstrate t hat vowel production skills improved to a greater degree through use o f a multichannel cochlear implant than through use of the Tactaid 7.