Background. Decreased sound intolerance (DST) is a disabling transdiagnostic phenomenon with high clinical relevance in autism. Neurodevelopmental DST is often studied as part of a general multisensory construct that includes both hyper- and hyposensitivity. Therefore, knowledge about the potential relevance of individual differences in the auditory modality is lacking. The purpose of the study was to begin to differentiate between commonly pooled auditory functions, by incorporating psychometric tools from the field of audiology. 

Methods. In a pilot sample (N = 520 adults, 23% autistic), we used Bayesian correlations to quantify the contribution of individual auditory items from the Glasgow Sensory Questionnaire to the degree of social, communicative and rigid autistic traits measured with the Broad Autism Phenotype Questionnaire (BAPQ) subscales. Then, we recruited an independent sample (N = 175 adults, 18% autistic) to measure, more specifically, 1) emotional reactions to sounds (affective DST), 2) speech understanding difficulties, and 3) non-social auditory processing (spatial perception and stream segregation), using self-report questionnaires. We used multiple regressions to test for associations with the autistic trait domains. 

Results. We found that all autistic traits measured by the BAPQ (social, communicative and rigid) linearly predicted affective DST, and these associations remained when autistic participants were excluded. Difficulties with speech perception, as well as spatial perception and auditory stream segregation, were most strongly predicted by communication differences. 

Conclusion. The robust relationship between autistic traits and emotional sound reactivity suggest that affective DST falls on a spectrum just like autism. This argues against strict dichotomization and encourages the use of continuous measures. The results support a dominant role for emotional and stress systems in autism-related DST, and may suggest that detailed audiological tests are clinically useful, in particular in the context of pragmatic language difficulties.