Decreased Sound Tolerance Disorders (Hyperacusis and Misophonia) in Cognitively Able Autistic Adults I: Prevalence and Clinical Features

Background: Decreased sound tolerance (DST; i.e., difficulty tolerating sounds in one’s environment) is one of the most common sensory features of autism, with a lifetime prevalence between 50–70%. Multiple disorders, including hyperacusis (the perception of moderate-intensity sounds as excessively loud or physically painful) and misophonia (a neuropsychiatric condition in which specific “trigger” sounds cause excessive emotional reactions such as anger, irritation, and disgust) likely contribute to the burden of DST in the autistic population, but there has been little exploration of this symptom cluster in autism in a way that distinguishes these conditions from each other or that examines how these disorders potentially differ in autistic and non-autistic individuals. Methods: A sample of 936 independent autistic adults was recruited from the Simons Foundation Powering Autism Research for Knowledge cohort. Hyperacusis and misophonia case status were operationalized using self-report survey items reflecting DST symptom endorsement and functional impairment. Descriptive statistics were derived to report on the prevalence of each DST category, as well as clinical features of individuals in both categories. Results: Across the sample, 40.2% met case criteria for hyperacusis (sex-weighted prevalence: 33.5%), whereas 35.5% met case criteria for misophonia (sex-weighted prevalence: 29.1%), and comorbid hyperacusis and misophonia was found in 27.0% (sex-weighted prevalence: 21.9%). Both hyperacusis and misophonia were associated with tinnitus and tinnitus disorder, although neither condition was associated with (diagnosed) hearing loss. Sound-evoked pain was a commonly reported symptom of hyperacusis, with 64.7% of autistic adults experiencing pain at least once per month and 24.7% of autistic individuals with hyperacusis meeting criteria for “pain hyperacusis.” Onset of hyperacusis was much earlier than previously reported in non-autistic samples, although most other features of both hyperacusis and misophonia did not differ from what is known from general population studies. Conclusion: Both hyperacusis and misophonia (and their comorbidity) are highly prevalent in the autistic population and should be studied in tandem (rather than as a unified construct) in future investigations of autism-associated DST.