Cross-Species Experiments Reveal Widespread Cochlear Neural Damage in Normal Hearing

Animal models suggest that cochlear afferent nerve endings may be more vulnerable than sensory hair cells to damage from acoustic overexposure and aging, but that such damage cannot be detected in standard clinical audiometry. Co-ordinated experiments in at-risk humans and a chinchilla model using two distinct physiological assays suggest that cochlear neural damage exists even in populations without clinically recognized hearing loss. Keywords: cochlear synaptopathy, hidden hearing loss, middle-ear reflex, chinchilla, aging