A comparative study of Mandarin compound vowels produced by prelingually deafened children with cochlear implants and normal hearing peers Free

The present study examined the dynamic features of compound vowels in native Mandarin-speaking children with cochlear implants (CIs). Fourteen prelingually deafened children with CIs (aged 2.9−8.3 years) and 14 age-matched, normal-hearing (NH) children produced monosyllables containing six Mandarin vowels (/aɪ/, /aʊ/, /uo/, /iɛ/, /iaʊ/, /ioʊ/). The frequency values of the first two formants were measured at nine equidistant time points (10-20-30-40-50-60-70-80-90%) over the course of vowel duration. All formant frequency values were normalized and then used to calculate vowel trajectory length, vowel section length, overall spectral rate of change, and vowel section rate of change. The results revealed that the CI children produced significantly longer durations for all six compound vowels. They clearly showed positional deviation from the NH children on vowels /aɪ/, /uo/ and /iɛ/. The CI children’s ability to produce formant movement for the compound vowels varied considerably. Some CI children produced relatively static formant trajectories for certain diphthongs whereas others produced certain vowels with greater formant movement than did the NH children. As a group, the CI children roughly followed the NH children on patterns of vowel dynamic spectral change, but they moved the articulators with a slower rate of change than did the NH children.