Relationship between tone perception and production in prelingually deafened children with cochlear implants.

HYPOTHESIS: Performance in tone perception and production are correlated in prelingually deafened pediatric cochlear implant (CI) users across individuals. Demographic variables, such as age at implantation, contribute to the performance variability.

BACKGROUND: Poor representation of pitch information in CI devices hinders pitch perception and affects perception of lexical tones in cochlear implant users who speak tonal languages.

METHODS: One hundred ten Mandarin-speaking, prelingually deafened CI subjects and 125 typically developing, normal-hearing subjects were recruited from Beijing, China. Lexical tone perception was measured using a computerized tone contrast test. Tone production was judged by native Mandarin-speaking adult listeners as well as analyzed acoustically and with an artificial neural network. A general linear model analysis was performed to determine factors that accounted for performance variability.

RESULTS: CI subjects scored ≈ 67% correct on the lexical tone perception task. The degree of differentiation of tones produced by the CI group was significantly lower than the control group as revealed by acoustic analysis. Tone production performance assessed by the neural network was highly correlated with that evaluated by human listeners. There was a moderate correlation between the overall tone perception and production performance across CI subjects. Duration of implant use and age at implantation jointly explained ≈ 29% of the variance in the tone perception performance. Age at implantation was the only significant predictor for tone production performance in the CI subjects.

CONCLUSION: Tone production performance in pediatric CI users is dependent on accurate perception. Early implantation predicts a better outcome in lexical tone perception and production.