Project Summary RestorEar Devices LLC aims to develop and test application of mild therapeutic hypothermia to mitigate noise- induced hearing loss (NIHL). NIHL is global public health risk and is an impairment resulting from irreversible damage caused to the sensitive structures and neural elements in the cochlea. A Center for Disease Control and Prevention report highlights that 24% of adults and 17% of teenagers in the United States experience hearing loss in one or both ears from exposure to occupational or recreational loud sound. NIHL has a high prevalence among members of the armed forces and firefighters who are occupationally at-risk. Globally, occupational noise exposure is responsible for 16% of disabling hearing loss (over 600 million people) with significant lifetime costs per person in the US alone. Preliminary and prior published results show that controlled and localized therapeutic hypothermia provided to the inner ear post-noise or surgical trauma conserves significant residual hearing and preserves sensitive neural structures. Over the past 3 years, the University of Miami team has also shown noise- induced changes in hearing and balance functions in at-risk groups of firefighters. With the prior Phase I SBIR award, RestorEar Devices LLC designed, built and tested systems and protocols to deliver mild therapeutic hypothermia non-invasively to the inner ear. We met all of the milestones outlined, including testing the efficacy of our devices for human application using computational models of heat transfer and studies from cadaveric temporal bones. We are now ready to translate one such device, ReBoundTM, to practice. This Phase II SBIR proposal will test safety and efficacy of ReBound-delivered mild therapeutic hypothermia treatment in mitigating noise-induced hearing loss in firefighters. In collaboration with the University of Miami and South Florida fire services, we have designed a clinical study to test this therapy in occupationally at-risk firefighters. Subjective and functional assessments repeated over time will enable evaluation of the protective effects of mild therapeutic hypothermia following noise exposure. Considering that the prevalence of hearing loss is expected to increase significantly in the next few decades, these human clinical studies will support establishing therapeutic hypothermia for hearing protection.