Manifestation of speech disfluencies in preschool Cantonese-English speaking bilingual children

Stuttering is characterised by disruptions in speech fluency that normally emerges between the ages of 2 to 5 when children start to formulate sentences. Current stuttering identification in children is largely based on speech disfluency criteria (>3% stuttering-like disfluencies, SLDs) developed for monolingual English-speaking children. Research in a Western language context shows that application of the criteria for monolingual to bilingual children may result in false positive diagnosis of stuttering. The applicability of these criteria to children speaking languages typologically distinct from English remains unclear. This preliminary study focused on bilingual Cantonese-English-speaking children, aiming to explore the manifestations of the speech disfluencies in Cantonese (a syllable-timed language) and English (a stress-timed language) while accounting for language dominance/proficiency and speaking task. Nineteen typically fluent Cantonese-English bilingual preschoolers were recruited for this study and their speech samples were collected across different speaking tasks (i.e. conversation and narration), and languages (i.e. Cantonese and English). The types and frequency of speech disfluencies were compared across both languages and the speaking tasks. The results showed that between 21-68% of children showed higher than 3% SLDs across different languages and speaking tasks. Linear mixed-effect analysis revealed that the prevalence of SLDs is higher in English (less dominant language) than Cantonese (more dominant language), and the prevalence is also higher in narration than conversation. These findings suggest the need for tailored stuttering identification criteria for bilingual children speaking diverse languages and emphasise the importance of considering language dominance/proficiency and speaking task when assessing stuttering in bilingual populations.