Device and Fitting Protocol for a Transitional Intervention for Debilitating Hyperacusis.

PURPOSE: This report describes a hearing device and corresponding fitting protocol designed for use in a transitional intervention for debilitating loudness-based hyperacusis. METHOD: The intervention goal is to transition patients with hyperacusis from their typical counterproductive sound avoidance behaviors (i.e., sound attenuation and limited exposure to healthy low-level sounds) into beneficial sound therapy treatment that can expand their dynamic range to the point where they can tolerate everyday sounds and experience an improved quality of life. This requires a combination of counseling and sound therapy, the latter of which is provided via the hearing device technology, signal processing, and precision fitting approach described in this report. The device combines a miniature behind-the-ear sound processor and a custom earpiece designed to maximize the attenuation of external sounds. Output-limiting loudness suppression is used to restrict exposure to offending high-level sounds while unity gain amplification maximizes exposure to healthy and tolerable lower level sounds. The fitting process includes measurement of the real-ear unaided response, the real-ear measurement (REM) system noise floor, the real-ear occluded response, real-ear insertion gain, and the output limit. With these measurements, the device can achieve the prescribed unity gain needed to provide transparent access to comfortable sound levels. It also supports individualized configuration of the therapeutic noise from an on-board sound generator and adaptive output limiting based on treatment-induced increases in dynamic range. RESULTS AND CONCLUSION: The utility of this device and fitting protocol, in combination with structured counseling, is highlighted in the outcomes of a successful 6-month trial of the transitional intervention described in a companion report in this issue.

Results of a 6-Month Field Trial of a Transitional Intervention for Debilitating Hyperacusis.

PURPOSE: We present results from a 6-month field trial of a transitional intervention for debilitating primary hyperacusis, including a combination of structured counseling; promotion of safe, comfortable, and healthy sound exposure; and therapeutic broadband sound from sound generators. This intervention is designed to overcome barriers to successful delivery of therapeutic sound as a tool to downregulate neural hyperactivity in the central auditory pathways (i.e., the maladaptive mechanism believed to account for primary hyperacusis) and, together with the counseling, reduce the associated negative emotional and physiological reactions to debilitating hyperacusis. METHOD: Twelve adults with normal or near-normal audiometric thresholds, complaints consistent with their pretreatment loudness discomfort levels ≤ 75 dB HL at multiple frequencies, and hearing questionnaire scores ≥ 24 completed the sound therapy-based intervention. The low-level broadband therapeutic sound was delivered by ear-level devices fitted bilaterally with either occluding earpieces and output-limiting loudness suppression (LS; to limit exposure to offensive sound levels) or open domes to maximize comfort and exposure to sound therapy. Thresholds for LS (primary outcome) were incrementally adjusted across six monthly visits based on treatment-driven change in loudness judgments for running speech in sound field. Secondary outcomes included categorical loudness judgments, speech understanding, and questionnaires to assess the hyperacusis problem, quality of life, and depression. An exit survey assessed satisfaction with and benefit from the intervention and the counseling, therapeutic sound, and LS components. RESULTS: The mean change in LS (34.8 dB) was highly significant (effect size = 2.045). Eleven of 12 participants achieved ≥ 16-dB change in LS, consistent with highly significant change in sound-based questionnaire scores. Exit surveys indicated satisfaction with and benefit from the intervention. CONCLUSION: The transitional intervention was successful in improving the hyperacusis conditions of 11 of 12 study participants while reducing their sound avoidance behaviors and reliance on sound protection.

A Sound Therapy-Based Intervention to Expand the Auditory Dynamic Range for Loudness among Persons with Sensorineural Hearing Losses: A Randomized Placebo-Controlled Clinical Trial.

The primary aim of this research was to evaluate the validity, efficacy, and generalization of principles underlying a sound therapy-based treatment for promoting expansion of the auditory dynamic range (DR) for loudness. The basic sound therapy principles, originally devised for treatment of hyperacusis among patients with tinnitus, were evaluated in this study in a target sample of unsuccessfully fit and/or problematic prospective hearing aid users with diminished DRs (owing to their elevated audiometric thresholds and reduced sound tolerance). Secondary aims included: (1) delineation of the treatment contributions from the counseling and sound therapy components to the full-treatment protocol and, in turn, the isolated treatment effects from each of these individual components to intervention success; and (2) characterization of the respective dynamics for full, partial, and control treatments. Thirty-six participants with bilateral sensorineural hearing losses and reduced DRs, which affected their actual or perceived ability to use hearing aids, were enrolled in and completed a placebo-controlled (for sound therapy) randomized clinical trial. The 2 × 2 factorial trial design was implemented with or without various assignments of counseling and sound therapy. Specifically, participants were assigned randomly to one of four treatment groups (nine participants per group), including: (1) group 1-full treatment achieved with scripted counseling plus sound therapy implemented with binaural sound generators; (2) group 2-partial treatment achieved with counseling and placebo sound generators (PSGs); (3) group 3-partial treatment achieved with binaural sound generators alone; and (4) group 4-a neutral control treatment implemented with the PSGs alone. Repeated measurements of categorical loudness judgments served as the primary outcome measure. The full-treatment categorical-loudness judgments for group 1, measured at treatment termination, were significantly greater than the corresponding pretreatment judgments measured at baseline at 500, 2,000, and 4,000 Hz. Moreover, increases in their "uncomfortably loud" judgments (∼12 dB over the range from 500 to 4,000 Hz) were superior to those measured for either of the partial-treatment groups 2 and 3 or for control group 4. Efficacy, assessed by treatment-related criterion increases ≥ 10 dB for judgments of uncomfortable loudness, was superior for full treatment (82% efficacy) compared with that for either of the partial treatments (25% and 40% for counseling combined with the placebo sound therapy and sound therapy alone, respectively) or for the control treatment (50%). The majority of the group 1 participants achieved their criterion improvements within 3 months of beginning treatment. The treatment effect from sound therapy was much greater than that for counseling, which was statistically indistinguishable in most of our analyses from the control treatment. The basic principles underlying the full-treatment protocol are valid and have general applicability for expanding the DR among individuals with sensorineural hearing losses, who may often report aided loudness problems. The positive full-treatment effects were superior to those achieved for either counseling or sound therapy in virtual or actual isolation, respectively; however, the delivery of both components in the full-treatment approach was essential for an optimum treatment outcome.