Mandarin lexical tones identification among children with cochlear implants or hearing aids

摘要

Objectives: Mandarin Chinese is a lexical tone language that has four tones, with a change in tone denoting a change in lexical meaning. There are few studies regarding lexical tone identification abilities in deafened children using either cochlear implants (CIs) or hearing aids (HAs). Furthermore, no study has compared the lexical tone identification abilities of deafened children with their hearing devices turned on and off. The present study aimed to investigate the lexical tone identification abilities of deafened children with CIs or HAs. Methods: Forty prelingually deafened children (20 with CIs and 20 with HAs) participated in the study. In the HA group, 20 children were binaurally aided. In the CI group, all of the children were unilaterally implanted. All of the subjects completed a computerized lexical tone pairs test with their hearing devices turned on and off. The correct answers of all items were recorded as the total score and the correct answers of the tone pairs were recorded as subtotal scores. Results: No significant differences in the tone pair identification scores were found between the CI group and HA group either with the devices turned on or off ( t= 1.62, p= 0.11; t= 1.863, p= 0.07, respectively). The scores in the aided condition were higher than in the unaided condition regardless of the device used ( t= 22.09, p<. 0.001, in the HA group; t= 20.20, p<. 0.001, in the CI group). Significantly higher scores were found in the tone pairs that contained tone 4. Age at fitting of the devices was correlated with tone identification abilities in both the CI and HA groups. Other demographic factors were not correlated with tone identification ability. Conclusions: The hearing device, whether a hearing aid or cochlear implant, is beneficial for tone identification. The lexical tone identification abilities were similar regardless of whether the subjects wore a HA or CI. Lexical tone pairs with different durations and dissimilar tone contour patterns are more easily identified. Receiving devices at earlier age tends to produce better lexical tone identification abilities in prelingually deafened children.