Duration and amplitude of tone production in children with cochlear implants

Abstract

The purpose of the present study was two-fold: (1) to examine whether Mandarin-speaking children with CIs showed distinctive durational and amplitude features for the four lexical tones in their tone production; (2) to compare the duration and amplitude patterns of Mandarin lexical tones in monosyllables produced in citation form between CI children and age-matched normal-hearing (NH) children. The participants included 14 prelingually deafened Mandarin-speaking children with CIs and 14 NH children, all aged between 2.9 and 8.3 years old. Each participant produced five CV syllables (fa, fu, pi, xu, ke) in four tones through a tone drill activity. The vowel duration and rms amplitude values at nine equidistant time locations over the vowel duration were obtained. The results revealed that the CI children can produce distinctive duration and amplitude features for the four lexical tones. Their durational pattern and amplitude contours were highly similar to the NH children on tone 1, 2, and 4 but differed from the NH children on tone 3. In addition, NH children showed positively correlated amplitude contour and F0 contour but the CI children demonstrated inconsistent amplitude and F0 contours for tone 3. This finding suggested that the amplitude contour of a tone and the F0 contour of the same tone may not always be highly correlated.