Comparative analysis of vocal communication and atypicality in mandarin-speaking children with autism spectrum disorder, developmental delay, and typical development

Purpose: The current study aimed to examine the similarities and differences in vocal characteristics between Mandarin-speaking 36–72-month-old children with autism spectrum disorder (ASD), children with developmental delay (DD), and typically developing (TD) children. Methods: We analyzed vocal characteristics during parent–child free play. Video and audio samples were collected from 21 children with ASD, 18 children with DD matched groupwise for developmental level, and 15 TD children matched groupwise for chronological age. Results: Compared to children in the DD and TD groups, children with ASD exhibited a significantly higher proportion of nonspeech vocalizations (NSV, p<0.01), atypical vocalizations (ATY, p<0.001), noncommunicative vocalizations (NCV, p<0.001), and no response to others (NR, p<0.001). These four metrics were significantly correlated with children's performance on the developmental evaluation and intelligence test. Receiver operating characteristic analyses indicated that the area under the curve (AUC) ranged from 0.871–0.978, with moderate accuracy, when using these four metrics to differentiate between children with ASD and TD children; this value improved to 1.000 with high accuracy when combining the four metrics. The AUC ranged from 0.747–0.820 when using the four metrics to differentiate children with ASD from those with DD and improved to 0.857 when combining the four metrics. Conclusion: These preliminary data suggest that vocal communication and vocal atypicality may be unique features of children with minimally verbal ASD and that the four metrics—NSV, ATY, NCV, and NR—have the potential to be ASD behavioral markers in screening and diagnosis.