Declarative or declarative question?—On the acoustics of English prosody of Hong Kong trilingual children with autism spectrum disorder

Abstract

The current study investigated the production of English prosody (i.e., focus marking) of trilingual Cantonese children with autism spectrum disorder (ASD) and their typically developing (TD) peers (i.e., Cantonese and American English children without ASD) using declarative questions. Speech materials were segmented at word and syllable levels, and word duration, f0, f0 range and intensity were extracted. Acoustic data were fitted using linear mixed-effects models with different explanatory variables followed by a likelihood ratio test. Between group comparison showed that the ASD group had significantly more fluctuating f0 range in post-focus words than the TD groups, which is likely to be an indication of hypercorrection, i.e., over-application of perceived prosodic pattern in English declarative questions. Within groups, the Cantonese children showed different patterns to the English children in terms of the interaction between the acoustic measures and on-focus expansion and post-focus compression. The Cantonese ASD group showed some degree of post-focus compression in terms of duration and mean f0, while the Cantonese TD group only had such pattern in terms of mean f0. The English TD group had a tendency of on-focus expansion in terms of duration and f0 range, but post-focus words showed significantly higher mean f0 than the pre- and on-focus ones, probably due to the question intonation.