Noise-Induced Hearing Loss: An Update

Noise-induced hearing loss (NIHL) was first described under the umbrella of “acoustic trauma” in the 1930s, particularly in the setting of industrialization and the rise of modern warfare. 1-3 It has since been differentiated from acoustic trauma – which is defined as hearing loss caused by a single, brief exposure to a very loud sound – given its association with chronic, less intense noise exposure. 4 NIHL is defined as a permanent sensorineural hearing loss that develops gradually, initially involving higher hearing frequencies; it is mainly associated with damage to the cochlear hair cells in the context of a patient history of long-term exposure to dangerous levels of noise. 5 It is the second most common form of sensorineural hearing impairment, after presbycusis (age-related hearing loss), 6