Study Of The Tonal Acquisition Of Mandarin Speaking Children With Cochlear Implant

With the data of two mandarin-speaking children with cochlear implant from Beijing, the present study tries to investigate the acquisition of tone in the early language development. The recognizable words and utterances of two children were transcribed into IPA and five-point-scale tone letters with perception and acoustic methods. During the process, it is found that the tones in the data of the two children appear to be a kind of ’tone unicity’(there is mostly only one tone among the utterance). In the speech of one of the two children, there are mostly level tones. And among the speech of the other child, there are mostly falling tones. This phenomenon leads to the assumption that children’s ability to acquire tones starts to decline when children get a certain age.Therefore, two more experiments (tone production experiment and tone perception experiment) were conducted on another20children to confirm the assumption. With these two experiments, it was expected to figure out whether the children produce all the four tones, and whether the four tones can distinguish meanings in their languages. The result of the production experiment lends support to the assumptions. The children who got cochlear implant after3and a half years mostly produced their unitary tones in their speech (even this, we still cannot say they cannot produce the other tones). From the result of the perception experiment, it is shown that the level of tone-perception abilities of those children who got cochlear implant after 3and a half years old turns out to be far below the average level. That is to say tones do not distinguish meanings in their language.Thus, we have the conclusion that the device of tonal acquisition plays an important role and starts to decline after children get3years old.