Autism Spectrum Disorder (ASD) is a lifelong neurodevelopmental condition that affects an individual’s social communication, social interaction, and behavior (American Psychological Association, 2013). A striking feature that distinguishes some individuals with autism from their peers without autism is “atypical” prosody. A between-group study was conducted to investigate prosody, speech motor control, auditory processing of pitch, and trained listener ratings of prosodic “naturalness” among adolescents with ASD (n=17) compared to TD controls (n=17) matched for age, gender and language. The specific aims of this study were to: (1) determine if individuals with ASD have significant acoustic-perceptual differences in their receptive and expressive prosody; (2) identify the interrelationship between prosody and language, motor speech, and pitch processing abilities; and (3) investigate if there is an association between group membership (ASD vs. TD) and trained listener ratings of overall “naturalness” (natural versus unnatural) of the speakers’ speech. The findings of this study support that some individuals with autism perform with significantly less accuracy on receptive and expressive prosody tasks and had significantly longer duration of utterances in comparison to TD controls. There was a significant positive relationship between receptive vocabulary and expressive prosody in the ASD group, supporting the “Theoretical Interaction Model”, while expressive vocabulary and speech motor control did not explain variability in expressive prosody above and beyond receptive vocabulary
