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Cochlear Implants and Tonal Languages| old_uid | 13066 |
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| title | Cochlear Implants and Tonal Languages |
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| start_date | 2013/11/25 |
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| schedule | 11h-12h30 |
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| online | no |
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| details | Invités par l'équipe |
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| summary | Poor representation of pitch information in cochlear implant (CI) devices hinders pitch perception and affects perception of lexical tones in cochlear implant users who speak tonal languages. While accurate representation of lexical tones may not be essential for tonal language sentence recognition in quiet, it is particularly important for sentence recognition in noise. In the present study, 110 Mandarin-speaking, prelingually-deafened CI subjects (age: 2.5 - 16 years) and 125 typically developing, normal-hearing subjects (age: 3 - 10 years) were recruited from Beijing and Shanghai, China. Lexical tone perception in quiet and in noise (at +12, +6, 0, and -6 dB signal-to-noise ratios) 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. Prelingually-deafened children with CIs scored from chance level to nearly perfect performance on the lexical tone perception task. Moderate amount of noise had very small effects on tone perception in normal-hearing children but had tremendous effects on tone perception in children with CIs. Brand of CI device (i.e., Advanced Bionics, Cochlear, or MedEl) did not show any significant effects on tone perception performance. 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 (r = 0.94). There was a moderate correlation between the overall tone perception in quiet and tone production performance across CI subjects (r = 0.56). Duration of implant use and age at implantation jointly explained approximately 30% of the variance in the tone perception performance. Age at implantation was the only significant predictor for tone production performance in children with CIs. Thus, children with CIs demonstrate suboptimal tone perception in quiet but very poor tone perception in noise. Tone production performance in pediatric CI users is dependent on accurate perception. Early implantation predicts a better outcome in lexical tone perception and production. |
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| responsibles | Rämä, Izard |
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