Sixth International Conference on Spoken Language Processing
The purpose of this study was to determine whether prelingually deaf children fitted with a cochlear implant are able to identify Cantonese tones in monosyllabic words. Eight children participated in this study. The age of the children ranged between 4:06 and 8:11. The duration of the post-operative period varied between 11 and 41 months. All children were fitted with the Nucleus 24-channel cochlear implant system. The stimuli were the six contrastive Cantonese tones produced with the monosyllabic target word /ji/. Each stimulus represented a concrete object: for example, the target word uttered with the highlevel tone (/ji55/) means "clothing", while the same word produced with the low-level tone (/ji22/) means "two". The six target words were produced by a male native speaker of Cantonese within a carrier phrase. Listeners had to identify the target words, presented within the carrier phrase, by selecting one of two pictures. These pictures represented one of eight minimal pair contrasts: high- vs mid-level; high- vs low-level; mid- vs low-level; high-level vs high-rising; high-rising vs low-rising; low-rising vs low-level; low-falling vs low-rising; low-falling vs low-level. Within each trial, one picture represented the object corresponding to the word/tone that had been presented; the other picture represented the other word of a minimal pair. Subjects were tested individually in a soundproof room. Each contrast was presented sixteen times; each member of the minimal pairs was presented eight times for each contrast. The order of the stimuli was randomised. No feedback was given. The results showed that performance was at chance level (50%) for all contrasts: the percentage of correct responses for each contrast varied between 47 and 58%. An analysis of the data grouped by tones, rather than tone contrasts, revealed that none of the tones was identified above chance. These findings suggest that this group of cochlear implant users could not extract sufficiently accurate pitch information to identify Cantonese tones. The implications of this finding for the perception of pitch information through cochlear implants will be discussed.
Bibliographic reference. Ciocca, Valter / Aisha, Rani / Francis, Alex / Wong, Lena (2000): "Can cantonese children with cochlear implants perceive lexical tones?", In ICSLP-2000, vol.3, 754-757.