Speech-in-noise perception in autistic adolescents with and without early language delay

Speech-in-noise perception seems aberrant in individuals with autism spectrum disorder (ASD). Potential aggravating factors are level of linguistic skills and impairments in auditory temporal processing. Here, we investigated autistic adolescents with and without language delay as compared to non-autistic peers, and we assessed speech perception in steady-state noise, in temporally modulated noise, and in concurrent speech. We found that autistic adolescents with intact language capabilities and not those with language delay performed worse than NT peers on words-in-stationary-noise perception. For the perception of sentences in stationary noise we did not observe significant group differences, although autistic adolescents with language delay tend to perform poorer in comparison to their TD peers. We also found evidence for a robust deficit in speech-in-concurrent-speech processing in ASD independent of language ability, as well as an association between early language delay in ASD and inadequate temporal speech processing. We propose that reduced voice stream segregation and inadequate social attentional orienting in ASD result in disproportional informational masking of the speech signal. These findings indicate a severe speech-in-speech processing deficit in autistic adolescents with broad implications for quality of social communication.