A Study On Tone Perception And Production In Mandarin-Speaking Children With Cochlear Implants

Mandarin Chinese is a kind of tone language, wherein the tone of each monosyllable conveys lexical meaning. In clinical practice, the tone problem is ubiquity in cochlear implant (CI) children, which seriously affects their speech intelligibility. The purpose of this study is to find out the tone performance characteristics of the children with CI, including tone perception and production, and also to explore the methods of treatment for the tone disorders of these children.The tone perception study includes two parts. The first study is a comparative experimental study on tone perception of the two groups of children.45 prelingually deafened, native Mandarin-speaking children with CI, and 45 normal hearing children, with ages ranging from 2 to 4 yr, participated. The results show that:(1) The ability of tone perception of the children with CI is obviously weaker than the normal ones; (2)The background noise more seriously effects on the tone perception of the children with CI; (3)Tone perception of children with CI is not improved by age. In the second study, we discuss the characteristics of tone perception of the children with CI, and find that:(1)The children with CI distinguish tone 1 between the other three tones is easier than tone 2 versus tone 3,tone 2 versus tone 4 and tone 3 versus tone 4; (2) The difficulty order of the tone perception for the children with CI is:tone 1,tone2 and tone 3,tone 4, from easy to difficult.The tone production study also includes two parts. The first study is a comparative experimental study on tone production of the two groups of children. The subjects are as same as those in the tone perception study. The results show that:(1) The ability of tone production of the children with CI is obviously weaker than the normal ones; (2) Tone production of children with CI is not improved by age. And then we investigate the main errors of tone in monosyllable and its characteristics of children with CI through perception and acoustic analysis. The results show that there is significant differences among their performance in the four tone types for children with CI. Of the four tones, tone 2 is the most difficult tone for the children with CI to produce, tone 1 and tone 4 are the easiest. Error patterns of tone 1 substitution and tone 2 distortion are most frequent. And the FO contours of children with CI are different from that of the normal hearing children.According to the characteristics of the tone performance of the children with CI, we preliminarily discuss the treatment strategies of tone disorder through an intervention to the tone perception and production of a case with CI. Through the result, we confirm the importance and validity of tone treatment for the children with tone disorder.