Cochlear synaptopathy can result from various insults, including acoustic trauma, aging,
ototoxicity, or chronic conductive hearing loss. For example, moderate noise exposure in
mice can destroy up to∼ 50% of synapses between auditory nerve fibers (ANFs) and inner
hair cells (IHCs) without affecting outer hair cells (OHCs) or thresholds, because the
synaptopathy occurs first in high-threshold ANFs. However, the fiber loss likely impairs
temporal processing and hearing-in-noise, a classic complaint of those with sensorineural …