Shahid Beheshti University of Medical Sciences The Scientific Journal of Rehabilitation Medicine 2251-8401 15 1 2026 04 21 Decreased Sound Tolerance in Autism Spectrum Disorder: A Narrative Review of the Prevalence, Mechanisms, Assessment Tools, and Interventions for Hyperacusis and Misophonia Decreased Sound Tolerance in Autism Spectrum Disorder: A Narrative Review of the Prevalence, Mechanisms, Assessment Tools, and Interventions for Hyperacusis and Misophonia 2 19 1101867 10.32598/SJRM.15.1.3432 FA Vida Rahimi Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. & Department of Geriatric Health, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. 0000-0003-1867-4735 Journal Article 2025 11 28 <strong>Background and Aims</strong> Decreased sound tolerance (DST), including hyperacusis and misophonia, is one of the most prominent and disabling sensory features in autism spectrum disorder (ASD) and has significant consequences on the social, emotional, and cognitive functioning of these individuals. This phenomenon occurs due to the overlap of multilayered mechanisms in neural pathways and has been reported with high prevalence in individuals with ASD. This study aimed to review the literature on the prevalence, neural mechanisms, assessments, and interventions related to DST in individuals with ASD. <br /><strong>Methods </strong>This narrative review was conducted by searching for articles between 2000 and 2025 in PubMed, Scopus, Web of Science, and Google Scholar. The search was performed by combining keywords related to autism, sound sensitivity, DST, hyperacusis, misophonia, prevalence, neural mechanisms, assessment, and interventions. After the initial screening, 91 studies were included.<br /><strong>Results </strong>DST is significantly more prevalent in the autism population than in the general population, with hyperacusis (affecting approximately 27%-40%) and misophonia (affecting 12%–35% of individuals on the spectrum). Investigation of mechanisms suggests increased central gain, an imbalance in excitation/inhibition ratio, increased auditory cortex sensitivity, pattern changes in subcortical areas, and involvement of the anterior insula and amygdala. Assessments also included questionnaires, measurements of loudness discomfort levels, otoacoustic emissions, electrophysiological indices, and imaging. Interventions included modified cognitive-behavioral therapy, sound therapy, environmental modifications, and virtual/augmented reality technologies. <br /><strong>Conclusion </strong>DST in ASD is a multifactorial phenomenon that requires multidimensional assessment and integrated interventions. Given its high prevalence and significant impact on functioning, future research should focus on standardizing assessment tools, developing autism-specific treatment protocols, and directly evaluating the effectiveness of interventions with enough samples. <strong>Background and Aims</strong> Decreased sound tolerance (DST), including hyperacusis and misophonia, is one of the most prominent and disabling sensory features in autism spectrum disorder (ASD) and has significant consequences on the social, emotional, and cognitive functioning of these individuals. This phenomenon occurs due to the overlap of multilayered mechanisms in neural pathways and has been reported with high prevalence in individuals with ASD. This study aimed to review the literature on the prevalence, neural mechanisms, assessments, and interventions related to DST in individuals with ASD. <br /><strong>Methods </strong>This narrative review was conducted by searching for articles between 2000 and 2025 in PubMed, Scopus, Web of Science, and Google Scholar. The search was performed by combining keywords related to autism, sound sensitivity, DST, hyperacusis, misophonia, prevalence, neural mechanisms, assessment, and interventions. After the initial screening, 91 studies were included.<br /><strong>Results </strong>DST is significantly more prevalent in the autism population than in the general population, with hyperacusis (affecting approximately 27%-40%) and misophonia (affecting 12%–35% of individuals on the spectrum). Investigation of mechanisms suggests increased central gain, an imbalance in excitation/inhibition ratio, increased auditory cortex sensitivity, pattern changes in subcortical areas, and involvement of the anterior insula and amygdala. Assessments also included questionnaires, measurements of loudness discomfort levels, otoacoustic emissions, electrophysiological indices, and imaging. Interventions included modified cognitive-behavioral therapy, sound therapy, environmental modifications, and virtual/augmented reality technologies. <br /><strong>Conclusion </strong>DST in ASD is a multifactorial phenomenon that requires multidimensional assessment and integrated interventions. Given its high prevalence and significant impact on functioning, future research should focus on standardizing assessment tools, developing autism-specific treatment protocols, and directly evaluating the effectiveness of interventions with enough samples. https://medrehab.sbmu.ac.ir/article_1101867_fcd59c1bdacc143b2da9a2efc7d7f3e6.pdf