Ever gone temporarily deaf after encountering loud, unexpected noises or rocking out a little too close to the speakers at a music festival? Downright scary, isn’t it?
Once or twice probably won’t kill your hearing…yet. Your short-term loss is probably more a coping mechanism than an indication of a future deaf sentence, according to research by New Zealand and American scientists.
Researchers from the University of New South Wales, the University of California, San Diego, and the University of Auckland discovered that so-called reversible hearing loss protects the cochlea — otherwise known as the inner ear — from permanent damage.
“This explains why we lose our hearing for hours or days after we have been exposed to a rock concert, for example. The adaptation mechanism has been switched on,” observed head researcher and UNSW professor Gary Housley in a press release.
A protective mechanism
The findings, which appeared recently in the Proceedings of the National Academy of Sciences, concluded that when the inner ear endures high levels of noise, it releases the hormone ATP, which attaches to a receptor, temporarily reducing its sensitivity to sound and causing what seems like a hearing loss. Laboratory mice lacking the receptor experienced no hearing loss when blasted with loud noise but were more vulnerable to permanent deafness.
Having abundant ATP levels may cause your hearing to suffer temporarily but protect you in the long run. With lower ATP levels, you’re more susceptible to permanent hearing loss because your cochlea isn’t sensitive enough to shut down before irreversible damage starts to occur.
“If the efficiency of this gene varies between individuals, as is the case for many genes, it may go some way to explaining why some people are very vulnerable to noise, or develop hearing loss with age, and others don’t,” said UCSD’s Allen Ryan.
Even if you are fortunate to be well endowed on the ATP front, you should go to as great of lengths as possible to protect yourself. You may have escaped damage thus far, but don’t press your luck. Excessive noise, much like sun exposure, adds up, leading to permanent damage without safety precautions.
“It’s like sun exposure. It’s not the acute exposure but the chronic exposure that can cause problems years later,” Housley noted.
Our ears adapt to sound
The ear naturally adapts with each blast of music, each gunshot, each motorcycle roar. But too much of a loud thing can be just that — much too much for your hearing to tolerate.
“Because our hearing sensitivity adapts, we can withstand loud noise, but we can’t sense the absolute intensity of the sound. And if we exceed the safe-sound upper limit, we will damage our hearing — despite this protective adaptation mechanism we have discovered,” added Housley. “This is clearly the case for personal music devices; these deliver much higher sound levels into our ears than naturally occurred as our hearing sense evolved.”
The researchers are hopeful their discovery will pave the way to more effective noise protection.
How to keep Your hearing
Prevention, of course, is always the best policy, even if your genetics are on your side. Why chance permanent deafness if you can take charge of your hearing health?
The National Institute on Deafness and Other Communications Disorders offers the following guidelines for preventing temporary deafness:
1. Be aware of damaging noises around you that are at and above 85 decibels, and avoid as much as possible situations where you may encounter them. For example, a refrigerator’s hum and normal conversation come in at 45 and 60 decibels, respectively, while a siren’s scream and the blast of a firecracker range from 120 to 150 decibels, according to the NIDCD.
2. Use earplugs, especially those designed specifically for the noisy activity you’re involved in, be it music, hunting, or the like. Keep in mind that not all ear protection is created equal. What you wear to protect your hearing at a concert won’t be appropriate at a firing range or on a helicopter ride.
3. Make sure the hearing of the children around you is adequately protected.
4. Educate those around you about the adverse effects of noise.
5. Get a test if you suspect you have hearing loss.