Lay Listener Classification and Evaluation of Typical and Atypical Children's Speech

Verbal children with autism spectrum disorder (ASD) often also have atypical speech. In the context of the many challenges associated with ASD, do speech sound pattern differences really matter? The current study addressed this question. Structured spontaneous speech was elicited from 34 children: 17 with ASD, whose clinicians reported unusual speech prosody; and 17 typically-developing, age-matched controls. Multiword utterances were excerpted from each child's speech sample and presented to young adult listeners, who had no clinical training or experience. In Experiment 1, listeners classified band pass filtered and unaltered excerpts as "typical" or "disordered". Children with ASD were only distinguished from typical children based on unaltered speech, but the analyses indicated unique contributions from speech sound patterns. In Experiment 2, listeners provided likeability ratings on the filtered and unaltered excerpts. Again, lay listeners only distinguished children with ASD from their typically-developing peers based on unaltered speech, with typical children rated as more likeable than children with ASD. In Experiment 3, listeners evaluated the unaltered speech along several perceptual dimensions. High overlap between the dimensions of articulation, clearness, and fluency was captured by an emergent dimension: intelligibility. This dimension predicted listeners' likeability ratings nearly as well as it predicted their judgments of disorder. Overall, the results show that lay listeners can distinguish atypical from typical children outside the social-interactional context based solely on speech, and that they attend to speech intelligibility to do this. Poor intelligibility also contributes to listeners' negative social evaluation of children, and so merits assessment and remediation.