After intense noise exposure, the hair cells lie flat. If the noise is not too loud, they eventually right themselves. The threshold shift is temporary.
“But Kujawa and Liberman have found that even though the threshold reverts to normal, permanent damage may have occurred. … [They] found that the damage occurs not in the hair cells themselves, which may recover, but in the spiral ganglion cells (SGCs — the cells in the cochlear neurons). The hair cells communicate with SGCs in the process of passing information to the brain.
“Although hearing is restored, the damage is done almost instantaneously. … Even though we think of this kind of hearing loss as related to aging, the truth is that ears are most vulnerable to noise damage when they’re young. … Teenagers — with their ubiquitous iPods and MP3 players, not to mention noise exposure from video games, loud stadiums, and rock concerts — are experiencing these loud noises at an especially vulnerable age. Another vulnerable population, newborn infants, might suffer damage from continuous noise in a neonatal ICU or from a white noise machines parents sometimes use to help fussy infants sleep.”
Author: Katherine Bouton
Title: Shouting Won’t Help
Publisher: Sarah Crichton Books
Date: Copyright 2013 by Katherine Bouton