Our Research Lab

Novel Treatment for Hyperacusis

The purpose of this NIH-Funded study (R21 DC015054) is to evaluate a rehabilitation protocol that could allow persons with hyperacusis (abnormal sensitivity to mid-level and high-level everyday sounds) to return to normal daily activities without the need for earplugs or muffs. This study incorporates counseling with the use of a multi-function device to provide sound attenuation and to generate therapeutic sound. Over time, the sound generator may permit reduction of the sound attenuation so that people who suffer from hyperacusis can return to normal sound tolerance.

Among the most desperate and memorable patients for hearing health-care providers are those who suffer a debilitating intolerance to the loudness of everyday sounds. This classical condition, known as hyperacusis, presents a unique treatment challenge. The most common audiometric evidence of hyperacusis is an abnormally small difference between the softest sound a person can detect (audiometric threshold) and the loudest sound a person will tolerate (loudness discomfort level or LDL). Persons with hyperacusis characteristically present in the clinic wearing earplugs and/or earmuffs to limit offending sound exposures, and commonly report withdrawal from routine daily activities, including those at work and home. Importantly, limited exposure to healthy sound levels actually exacerbates the hyperacusis condition.

Profound hyperacusis (abnormally small dynamic range) in a person with normal audiometric thresholds.

The primary challenge for the clinician is to transition the debilitated patient out of sound-attenuating hearing protection (which when used for prolonged periods is counterproductive and may further exacerbate hyperacusis) and into a sound-enriching therapy to promote normal sound tolerance. The dilemma for the clinician, in the absence of an efficient and effective intervention strategy, is how best to facilitate the transition of the patient, who may often cling to sound protection, into productive sound-enriching treatment. We are attacking this quandary with an extreme form of amplitude compression that has been advocated as an alternative to sound-attenuating protection for facilitating desensitization of debilitated hyperacusis patients. Our “loudness suppression” scheme will be implemented in bilateral customized combination hearing-aid/noise generator devices, deeply seated within the ear canals and acoustically sealed for maximum sound attenuation (offset by unity gain). This device offers, in a single flexible instrument, a promising transitional intervention to sound-enriching therapy, replacing counterproductive sound-attenuating earplugs with loudness-suppressing compression processing that affords improved audibility and a broader dynamic range, ostensibly without opposing the therapeutic effects of enriching sound therapy. In this project, engineering, implementation, and validation of the compression processing and sound therapy device was completed in Phase 1.

 

Sample device and research software platform.

In Phase 2, the device, used as a transitional tool to replace maladaptive hearing protection, will be assessed together with enriching sound therapy from noise generators and scripted patient counseling in a repeated-measures within-subject design to track treatment effects and dynamics in patients with debilitating hyperacusis. The results from this high-impact research will guide and shape innovative sound-based interventions to streamline treatment and enhance the well-being and quality of life for severely affected hyperacusis patients.

We have just completed our first research study with this novel treatment and the outcomes were extremely encouraging. We now are writing up our results for publication and seeking funding for our next, larger-scale investigation of efficacy.