Funding for this study ended prior to enrollment of any participants.

There are no widely available treatments for the underserved populations with tinnitus, hyperacusis, and hearing-in-noise deficits. Left unmanaged, these disorders can lead to a wide range of negative psychosocial and emotional sequelae including anxiety, depression, fear, and social isolation. The proposed research will investigate a novel closed-loop sound therapy designed to address the mutual basis of these disorders.

Upwards of 700 million people are projected to require rehabilitative services for hearing disorders by the year 2050 (Chadha, Kamenov, & Cieza, 2021). Many will suffer not from what is inaudible but from the presence of insuppressible sound. Individuals may be overwhelmed by phantom sounds that do not exist external to the auditory system (tinnitus) (Henry, Dennis, & Schechter, 2005). Moderate intensity sounds may have malformed percepts that induce loudness, annoyance, fear, or pain (hyperacusis) (Tyler et al., 2014). Sounds may also appear engulfed by other noises in the environment (Plack, Barker, & Prendergast, 2014). These hearing disorders are co-morbid with one another with roughly 80% of tinnitus patients reporting reduced sound level tolerance (Anari et al., 1999). Hyperacusis, tinnitus, and hearing-in-noise deficits are common chronic disorders within middle-aged/older adults but can also affect younger ages, with noise exposure history and traumatic brain injuries as key predictors. The outlined hearing disorders are complicated and heterogeneous making them challenging to treat. Consequently, despite a clear demand for rehabilitative services, there are no widely accepted nor effective treatments available (Baguley and Hoare, 2018). The result of this is typified in tinnitus patients, of whom 84.8% have never attempted any form of remedy (Bhatt, Lin, & Bhattacharyya, 2016).

We propose a therapeutic strategy that is founded upon the most beneficial aspects of previously conducted randomized controlled trials (RCTs). Namely, the therapy will employ a closed-loop system. The research capitalizes on promising findings from current studies in animal models, seeking to take advantage of the neuroscience principles thought to operationalize paired plasticity. The therapy is entirely non-invasive, posing minimal risk to the patient, and is translatable to widely available hardware. The research will use a "gold-standard" randomized, double-blinded, placebo-controlled clinical trial to objectively evaluate its worth.

Inclusion Criteria:

• Normal audiometric thresholds
• Subjects with tinnitus will have self-reported chronic tinnitus that has persisted for the duration of at least 6 months
• Subjects with hyperacusis will have a clinical diagnosis of hyperacusis and/or self-reported sound tolerance complaints that have persisted for the duration of at least 6 months

Exclusion Criteria:

• Conductive hearing loss (as assessed by audiologist)
• Active otologic disease (as assessed by audiologist)
• Significant cognitive decline (Montreal Cognitive Assessment score > 25)