The perception of lexical tone contrasts in Cantonese children with and without specific language impairment (SLI)

This study examined the perception of fundamental frequency (f0) patterns by Cantonese children with and without specific language impairment (SLI).

Participants were 14 five-year-old children with SLI, and 14 age-matched (AM) and 13 four-year-old vocabulary-matched (VM) controls. The children identified a word from familiar word pairs that illustrated the 8 minimally contrastive pairs of the 6 lexical tones. They discriminated the f0 patterns within contrastive tonal pairs in speech and nonspeech stimuli.

In tone identification, the SLI group performed worse than the AM group but not the VM group. In tone discrimination, the SLI group did worse than the AM group on 2 contrasts and showed a nonsignificant trend of poorer performance on all contrasts combined. The VM group generally did worse than the AM group. There were no group differences in discrimination performance between speech and nonspeech stimuli. No correlation was found between identification and discrimination performance. Only the normal controls showed a moderate correlation between vocabulary scores and performance in the 2 perception tasks.

The SLI group's poor tone identification cannot be accounted for by vocabulary knowledge alone. The group's tone discrimination performance suggests that some children with SLI have a deficit in f0 processing.