In “High-Tech Hope for the Hard of Hearing,” David Owen, The New Yorker, has written an article that gives us a good look at what scientists know about hearing loss and where they are finding possibilities for treatment and, possibly, a cure. He begins his article with a series of personal anecdotes about himself, his family, and friends and the hearing problems they’ve developed due to exposure to loud noise and other factors. Owen’s interest in this story is motivated, at least in part, by his tinnitus, which is marked by a constant high-pitched ringing in his ears.
Among the advances that Owen examines, he discusses the discovery of hidden hearing loss and introduces us to Charles Liberman, who, with his colleague Sharon Kujawa, “solved a mystery that had puzzled some audiologists for years: the fact that two people with identical results on a standard hearing test, called an audiogram, could have markedly different abilities to understand speech, especially against a background of noise.” He writes that “[s]cientists had known for a long time that most hearing impairment involves damage to the synapses and nerve fibres to which hair cells are attached, but they had assumed that the nerve damage followed hair-cell loss, and was a consequence of it.” What Liberman and Kujawa discovered is that “the connections between the sensory cells and the nerve fibres that go first.” And the reason this early damage isn’t picked up by a standard hearing test is because it measures “the ability to detect pure tones along a scale of frequencies [which] requires only functioning hair cells…and is unaffected by nerve damage until more than eighty per cent of the synapses are gone.”
“A disturbing implication of [Liberman and Kujawa’s] finding is that hearing can be damaged at decibel levels and exposure times that have traditionally been considered safe,” writes Owen, but he is reassured by the researchers that the discovery of hidden hearing loss is cause for optimism. Why? “[B]ecause reconnecting nerve synapses is almost certain to be easier than regenerating functioning hair cells inside human ears.” In fact, Owen tells us that Liberman and others “have successfully restored some damaged connections in lab animals, and [Liberman] believes that far greater advances are to come.”
While cause for optimism is welcome, Owen notes something early in his article that is particularly frustrating to those advocating for regulation of noise:
There are also increasingly effective methods of preventing damage in the first place, and of compensating for it once it’s occurred. The natural human tendency, though, is to do nothing and hope for the best, usually while pretending that nothing is wrong.
Click the link above to read this interesting and hopeful article in full.