The Relation Between Cochlear Neuropathy, Hidden Hearing Loss and Obscure Auditory Dysfunction

Abstract

Sensorineural hearing loss is typically defined by threshold elevation, often resulting from dysfunction of cochlear outer hair cells. Damage can occur as a result of ageing and noise exposure, reducing auditory sensitivity, and allowing detection using pure tone audiometry, the cornerstone of audiological testing. Yet the audiogram is limited in its ability to predict perceptual performance, especially for speech perception in noise. The deficits reported in some audiometrically normal listeners provide stark examples of this insensitivity. Recent research in animals has revealed that widespread loss of auditory nerve fibers can take place without hair cell loss or threshold elevation, as a result of either noise exposure or ageing. This pattern of damage may manifest as “hidden hearing loss” in humans, leading to perceptual deficits without affecting the audiogram. A great deal of interest is currently focused on this condition and its putative effects, which are expected to impact listening in complex ...