Tone production in Mandarin-speaking children with cochlear implants: apreliminary study

Abstract

ObjectiveMore than a quarter of the world's population speak tone languages, such as Mandarin Chinese. In thoselanguages, the pitch or tone pattern of a monosyllabic word conveys lexical meaning. The purpose of this study was toinvestigate tone production in Mandarin-speaking children with cochlear implants (CIs).Material and MethodsSpeech samples were recorded from seven normal-hearing and four CI children aged 4–9 years. Allsubjects were native Mandarin speakers. The speech samples were used for acoustic analysis of the tone patterns, i.e. thefundamental frequency contours. In addition, a tone intelligibility test was carried out in which four normal-hearing nativeMandarin-speaking adults listened to the speech materials and judged the intelligibility of the children's tone production.ResultsThe tone production for the seven normal-hearing children was considered to be perfect in the intelligibility test.Acoustic analysis of the speech materials of the normal-hearing children produced the four typical tone patterns ofMandarin Chinese: (i) high and flat; (ii) rising; (iii) low and dipping; and (iv) falling. The tone patterns produced by thechildren with CIs tended to be flat, with some other patterns being irregular. The results of the tone intelligibility tests alsoshowed degraded intelligibility of tone patterns.ConclusionA potential speech development deficit was documented in prelingually deafened children with CIs whosenative language is a tone language. The imperfect tone production of the implant children, which can be attributed to thepaucity of pitch information delivered via the current CI stimulation, may have significant implications for communicationusing tone languages. Further research is warranted to determine factors that may affect tone development in children withCIs.