Transitional Intervention for Hyperacusis in Autism

Background: Loudness hyperacusis, "an unusual intolerance to the loudness of ordinaryenvironmental sounds," is a core feature of autism spectrum disorder (ASD) as recognizedby the American Psychiatric Association. Loudness hyperacusis affects 37 to 46% ofautistic people, yet despite this pervasiveness, there is no standard treatment and theevidence supporting existing treatments is low. The lack of effective treatment isconsistent with weak evidence for successful interventions for other sensory deficitsassociated with ASD. Combined with sound‐related discomfort, annoyance, anxiety, fear,and even pain, loudness hyperacusis can have life‐altering effects impacting socialwell‐being, employment, healthcare seeking behaviors, and risk of self‐harm. The presenceof ASD compounds the risk for such consequences. Recognizing these impacts, autisticpeople indicate that development of hyperacusis treatments is a top priority for autismresearch.Objectives: The objective of this intervention is to address the problem of LH in ASD bytransitioning individuals from their typical counterproductive sound avoidance behaviors(i.e., overuse of sound‐attenuating hearing protection devices and self‐imposed limitedexposure to healthy low‐level sounds) into beneficial sound therapy treatment that canexpand their dynamic range for sound intensity to the point where they can tolerateeveryday sounds and experience an improved quality of life. A similar intervention, whichcombines structured counseling, protective sound management, and sound therapy hassucceeded in significantly expanding the dynamic range of hearing for non‐autistic adultswith LH.Hypothesis: It has been proposed that enhanced neural gain in the central auditorypathway is responsible for loudness hyperacusis (LH) in individuals with ASD. Therefore,we hypothesize that our transitional intervention for hyperacusis in autism (TIHA) will:(1) expand the dynamic range for sound intensity in individuals with ASD and (2) reduceor suppress the enhanced central gain associated with LH.Specific Aim: The specific aim of this clinical trial is to evaluate the effectiveness,benefits, and post‐treatment persistence of an intervention for LH in adults, ages 18 to39 years, with ASD, normal intelligence, and a primary auditory complaint ofmild‐to‐severe LH.Study Design: This multi‐site (University of Central Florida, University of Texas atDallas) trial will enroll 40 autistic adults with mild‐to‐severe hyperacusis, asindicated by a score ≥ 22 on the Hyperacusis Questionnaire (HQ) and LDLs for tones ≤ 80dB HL at two or more audiometric frequencies. In the randomized, within‐person,repeated‐measures, waitlist‐controlled full crossover design, participants will berandomized into one of two groups. Group AB receives the 6‐month intervention followed bya 6‐month "watchlist" period. Group B begins in the 6‐month waitlist control periodfollowed by the 6‐month intervention. Primary and secondary outcomes will be measuredmonthly and evaluated in an intention‐to‐treat analysis of all available data.Clinical Impact: With high prevalence and associated risks, the impact of untreated LH inASD can be severely debilitating and life altering. Transitioning this population out ofcounterproductive sound avoidance behaviors by expanding their dynamic range for soundintensity can enhance social engagement, expand the set of routinely sampledenvironments, and open learning, recreational, and vocational opportunities not currentlyavailable because of decreased sound tolerance. Following successful completion of thisclinical trial, much needed information about treatment dynamics and maintenance dosingwill be available to guide subsequent research and clinical applications of theintervention concepts and principles for other hyperacusic individuals with ASD,including children and those adults with more severe and complex involvement. Potentialbenefits include reduced or eliminated counterproductive sound‐triggered behaviors andincreased attention, focus, and pleasure associated with daily activities limited bydecreased sound tolerance. Ultimately, the benefits of a successful intervention and thefindings from this completed trial will steepen learning and treatment trajectories whileproviding new and improved opportunities for the trial participants in their pursuit ofemployment, social opportunities that increase quality of life, and economic prosperity.Ultimately, these benefits, together with improved mental health outcomes subsequent tothe elimination of barriers to routine healthy sound exposures, can be expected toenhance the enjoyment of life for virtually all autistic people affected by hyperacusis.