Difficulty with selective listening in Autism spectrum disorder

Abstract

Individuals with autism spectrum disorder (ASD) often experience difficulty with selective listening in the presence of multiple sounds despite their normal puretone thresholds. We have been conducting a series of studies to uncover neural bases for such difficulty in ASD adults without intellectual disability. First, we compared basic auditory functions between ASD and neurotypical (NT) groups, and found that (1) sensitivities to interaural time and level differences were lower in ASD than NT, and (2) a sub-group of ASD showed low sensitivity to temporal fine structure of acoustic waveforms. These findings suggest deficits in auditory processing in the brainstem of ASD. Second, we compared target detection thresholds between the two groups in the presence of distractors having little energetic masking on the target. Detection performance was dependent on the spectrotemporal coherence of target and distractor components in NT, whereas no such difference was observed in ASD, suggesting that ASD may lack automatic grouping across frequency channels. Additionally, we have observed significant differences between the two groups in behavioral, perceptual, autonomic, and brain responses to speech and/or non-speech stimuli. Taken together, difficulty with selective listening in ASD may involve several different mechanisms in both cortical and sub-cortical neural sites.