By Nema Farouk Nasreldeen Hamid, Master in Clinical Audiology and Hearing Therapy

Hyperacusis is characterized by a heightened sensitivity to common environmental sounds that are typically not bothersome to most people (Vernon, 1987). It is often associated with other auditory disorders, such as tinnitus, and can co-occur with neurological and psychiatric conditions like autism spectrum disorders, migraine, and depression (Andersson et al., 2005). Everyday sounds are perceived as intolerably loud, annoying, or even painful. Hyperacusis can severely affect the quality of life, reducing sociability and increased stress (Attri & Nagarkar, 2010).

A lack of established procedures and evidence-based therapies makes diagnosing and treating hyperacusis which is typified by an abnormal intolerance to common environmental sounds extremely difficult. Several sound therapy techniques, such as the use of therapeutic sound and counseling, have been investigated in recent research on the management of hyperacusis. However, due to considerable variation in the type, level, and duration of sound exposure, the clinical usefulness of such a treatment has not been proven. Therefore, the purpose of the current systematic review was to investigate whether sound-based treatment programs may reduce the effects of hyperacusis.

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Using the Cochrane Library, Medical term (MeSH) search engine, all necessary key terms for ‘Hyperacusis’ and various sound-based management options for Hyperacusis were identified. Four keywords were used to search five major databases, including PUBMED, PROQUEST, SCOPUS & EMBASE. The articles obtained from the online search engine were screened. Title and abstract screening, full-text screening, and data extraction were done using Cochrane-recommended online systematic review software, ‘Rayaan’ (Ouzzani, 2016). Data extraction was carried out in a Microsoft Word document. The significant outcomes considered were the pre and post-scores of specific outcome measures, which were used to document the efficacy of the treatment program.

After eliminating duplicates, the first searches utilizing the keywords in the four databases produced 149 articles. Nine articles were ultimately chosen after the full texts of the fourteen articles were assessed. Based on the MMAT checklist on the extracted nine articles, one article was rated as having high bias, and eight articles were rated as having low bias. However, all nine articles were included for data synthesis. This review examined three randomized controlled trials, three pre-post studies, one retrospective study, and two case reports. While the majority of the studies focused on adults with sensorineural hearing loss along with normal hearing individuals. The extracted studies have used a variety of stimuli ranging from white noise to different kinds of environmental sounds. However, all the studies recommend the most comfortable level (MCL) as the initial presentation level and have either increased or reduced the intensity of stimulus based on the subject’s response. Most studies have used LDL or UCL as outcome measures pre and post-treatment to determine the efficacy of sound generators in reducing hyperacusis. Few studies have used structured interviews and self-reported questionnaires like the Tinnitus Handicap Inventory (THI), Hyperacusis Questionnaire (HQ), Khalfa hyperacusis questionnaire, and Tampa Scale for Hyperacusis to understand subjects’ perspective of improvement from treatment. All nine studies have reported a significant reduction in hyperacusis following treatment using sound generators. While a majority of the studies report improvement in LDL or UCL following treatment others have reported improvement in self-reported questionnaire scores documenting self-reported improvement following treatment. One study has even reported significant reductions in associated negative emotional reactions to target stimuli for all participants.

All nine studies have reported a significant reduction in hyperacusis following treatment using sound generators documenting the effectiveness of these therapy programs in reducing the debilitating effects of hyperacusis. However, there is a need for more controlled clinical trials to accurately assess the effectiveness of sound therapy for hyperacusis.