Transitional Intervention for Hyperacusis in Autism

Effectiveness of an Individualized Progressive Treatment for Expanding Sound Tolerance in Adults With Autism Spectrum Disorder: A Crossover Randomized Controlled Trial (RCT)

The main goal of this clinical trial is to evaluate the effectiveness, benefits, and post-treatment persistence of an intervention for loudness hyperacusis in adults with autism spectrum disorder (ASD). The main questions it aims to answer are:

• Does the intervention increase loudness tolerance
• Does the intervention reduce symptoms related to loudness hyperacusis Researchers will compare measures related to loudness hyperacusis before, during, and after the intervention.

Participants will:

• Be randomly assigned to either one of two groups. One group will receiver the intervention immediately. This group will be evaluated during the 6-month intervention and evaluated for 6 months after the end of the intervention. The other group will be evaluated for 6 months before the intervention and during the 6-month intervention.
• Visit the test site once every month over the course of a year for evaluation and intervention activities
• Keep a diary of their symptoms and the number of hours per day they engage in the intervention

Background: Loudness hyperacusis, "an unusual intolerance to the loudness of ordinary environmental sounds," is a core feature of autism spectrum disorder (ASD) as recognized by the American Psychiatric Association. Loudness hyperacusis affects 37 to 46% of autistic people, yet despite this pervasiveness, there is no standard treatment and the evidence supporting existing treatments is low. The lack of effective treatment is consistent with weak evidence for successful interventions for other sensory deficits associated with ASD. Combined with sound-related discomfort, annoyance, anxiety, fear, and even pain, loudness hyperacusis can have life-altering effects impacting social well-being, employment, healthcare seeking behaviors, and risk of self-harm. The presence of ASD compounds the risk for such consequences. Recognizing these impacts, autistic people indicate that development of hyperacusis treatments is a top priority for autism research.

Objectives: The objective of this intervention is to address the problem of LH in ASD by transitioning individuals from their typical counterproductive sound avoidance behaviors (i.e., overuse of sound-attenuating hearing protection devices and self-imposed limited exposure to healthy low-level sounds) into beneficial sound therapy treatment that can expand their dynamic range for sound intensity to the point where they can tolerate everyday sounds and experience an improved quality of life. A similar intervention, which combines structured counseling, protective sound management, and sound therapy has succeeded in significantly expanding the dynamic range of hearing for non-autistic adults with LH.

Hypothesis: It has been proposed that enhanced neural gain in the central auditory pathway 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) reduce or 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 to 39 years, with ASD, normal intelligence, and a primary auditory complaint of mild-to-severe LH.

Study Design: This multi-site (University of Central Florida, University of Texas at Dallas) trial will enroll 40 autistic adults with mild-to-severe hyperacusis, as indicated by a score ≥ 22 on the Hyperacusis Questionnaire (HQ) and LDLs for tones ≤ 80 dB HL at two or more audiometric frequencies. In the randomized, within-person, repeated-measures, waitlist-controlled full crossover design, participants will be randomized into one of two groups. Group AB receives the 6-month intervention followed by a 6-month "watchlist" period. Group B begins in the 6-month waitlist control period followed by the 6-month intervention. Primary and secondary outcomes will be measured monthly 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 in ASD can be severely debilitating and life altering. Transitioning this population out of counterproductive sound avoidance behaviors by expanding their dynamic range for sound intensity can enhance social engagement, expand the set of routinely sampled environments, and open learning, recreational, and vocational opportunities not currently available because of decreased sound tolerance. Following successful completion of this clinical trial, much needed information about treatment dynamics and maintenance dosing will be available to guide subsequent research and clinical applications of the intervention concepts and principles for other hyperacusic individuals with ASD, including children and those adults with more severe and complex involvement. Potential benefits include reduced or eliminated counterproductive sound-triggered behaviors and increased attention, focus, and pleasure associated with daily activities limited by decreased sound tolerance. Ultimately, the benefits of a successful intervention and the findings from this completed trial will steepen learning and treatment trajectories while providing new and improved opportunities for the trial participants in their pursuit of employment, social opportunities that increase quality of life, and economic prosperity. Ultimately, these benefits, together with improved mental health outcomes subsequent to the elimination of barriers to routine healthy sound exposures, can be expected to enhance the enjoyment of life for virtually all autistic people affected by hyperacusis.

Inclusion Criteria

• Adults age 18 to 39 years
• Autism spectrum disorder
• Mild-to-severe loudness hyperacusis indicated by a score ≥ 22 on the Hyperacusis Questionnaire (HQ) and LDLs for tones ≤ 80 dB HL at two or more audiometric frequencies in at least one ear.
• No more than slight or mild sensorineural hearing loss from 250 to 8000 Hz
• Normal tympanograms consistent with normal middle ear function
• Normal "tone" decay response for "comfortable but soft" broadband noise
• Ability understand informed consent in English
• Availability and willingness to conform to the study visit schedule
• Diagnosis of autism (including Asperger's and other diagnoses "on the spectrum")
• Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R) score of 65 or greater to confirm ASD diagnosis
• Full-Scale IQ score of 90 or greater on the Weschler Abbreviated Scale of Intelligence (WASI-II; 2-lists).

Exclusion Criteria

• Management for head trauma within the past 6 months
• Management for traumatic brain injury within the past 6 months
• Management for epilepsy within the past 6 months
• Management for seizures within the past 6 months
• Management for or other neurological disorders within the past 6 months
• Otologic surgical procedures within the past 6 months
• Actively fluctuating hearing loss within the past 6 months
• Acute Meniere's disease within the past 6 months
• Labyrinthitis within the past 6 months
• Conductive hearing loss
• Otalgia
• Ongoing use of ototoxic medications.
• Active or past drug or alcohol dependent histories
• Known scheduling or travel conflicts