Native and non-native listeners' judgements on the overall speech quality of hearing-impaired children

This study focuses on the influence of listeners' native language on their judgement of the overall speech quality of normally hearing (NH) and hearing-impaired (HI) children. Studies have shown that listeners' native language influences their judgements on linguistic aspects of a foreign language. Since judging speech quality does in principle not require any knowledge of the language, the question arose if the native language influences listeners' judgements. For this purpose, the overall speech quality of seven-year-old Dutch speaking children (n = 21) with an acoustic hearing aid (HA), a cochlear implant (CI) and normal hearing (NH) was judged by four listener groups (native speakers of Italian, German, French and Dutch). Listeners completed a comparative judgement task in which stimuli were presented in pairs. For each pair, they selected the better sounding stimulus. This procedure ultimately led to a ranking of the stimuli according to their speech quality. The ranking showed that NH children had a significantly higher speech quality than HI children. Interestingly, there was no significant effect of language background. Both native and non-native listeners perceived a significant difference in speech quality. Also, within the group of HI children, all listener groups preferred the speech of CI children when comparing them to HA children. These results indicated that the differences were purely speech related since the non-native listeners had no linguistic knowledge of Dutch. Considering that all listeners perceived a similar qualitative difference, we conclude that there was no transfer of native language in this type of judgement.