2025 NHCA Annual Conference

In 2009, damage to the synapses connecting the inner hair cells to the auditory nerve fibers was identified as one of the earliest noise-induced pathologies in the cochlea. Since then, there has been tremendous interest in the identification of damage-risk relationships in rodent models. In addition, there have been many efforts to translate these findings from rodent models to humans. Whereas studies in rodents and non-human primates have been rigorously controlled using a single exposure to calibrated noise, studies in humans have attempted to estimate the cumulative effects of lifetime exposure and seek associations between exposure estimates and functional measurements, and identify biomarkers for specific damage, such as cochlear synaptopathy. This session will review the current understanding of noise-induced cochlear synaptopathy in rodents, non-human primates, and humans, and provide an overview of key questions in the application of these data to workers with chronic exposure to noise in the workplace. An overview of new studies assessing chronic noise exposure in non-human primates will be provided. In addition, this session will provide practical take home messages you can share with patients who have questions about noise-induced hearing deficits beyond the audiogram.

Learning Objectives:
1. Summarize the current understanding of noise-induced cochlear synaptopathy damage-risk relationships in rodents
2. Describe the current status of cochlear synaptopathy research in non-human primates
3. Provide appropriate messaging regarding the risks of noise-induced cochlear synaptopathy in humans exposed to occupational noise and other loud sound exposures