You don’t need me to tell you that loud noise and loud music can destroy your hearing. That’s very well-known.
But just as worrying – you have another body part that is vulnerable to damage from these sounds.
According to researchers at the University of Southern California (USC), two types of damage occur during and after you are exposed to loud sounds. Many of the sensory hair cells in your ears, cells that send neural messages, are destroyed. After that, your inner ear fills up with fluid that leads to the death of neurons.1
“That buildup of fluid pressure in the inner ear is something you might notice if you go to a loud concert,” says researcher John Oghalai. “When you leave the concert, your ears might feel full and you might have ringing in your ears. We were able to see that this buildup of fluid correlates with neuron loss.”
Right now, once those neurons die, there’s no treatment that can replace them.
But the USC scientists are working on a tool to keep most of the neurons from being killed. They’ve found evidence that a salt and sugar solution injected through the eardrum into the middle ear after noise exposure can limit neuron death.
They envision the injection will someday be carried by military personnel to treat their ears after being exposed to loud explosions in battle.
You May Need to do More
But some damage may be too deep for a salt and sugar wash. Other research indicates that the neuron harm from noise goes deeper into the brain – altering how your brain processes speech in the brain’s auditory cortex.
Lab tests at the University of Texas at Dallas show that severe hearing loss puts a large number of neurons in the auditory cortex out of business.2 These traumatized cells go dormant and don’t respond to sound at all any more. And many of the remaining cortical neurons, although still able to react to sound, behave in slow motion, sending signals more slowly and with less accuracy.
In contrast, moderate hearing loss doesn’t destroy any neurons, but it does lengthen the time they need to respond to sound, according to this study. And the neurons are less sensitive, requiring louder sounds to provoke a reaction.
All of these neuronal changes hamper your intellectual abilities – making it harder to engage in conversation and complicating your attempts to communicate. This can result in social isolation, which is known to make people more vulnerable to Alzheimer’s disease or other cognitive problems.
“Although the ear is critical to hearing, it is just the first step of many processing stages needed to hold a conversation,” says researcher Michael Kilgard. “We are beginning to understand how hearing damage alters the brain and makes it hard to process speech, especially in noisy environments.”
Sounds that are Hard to Avoid
Even if you avoid loud music and other deafening noises, living in or near a noisy environment – like the racket of a restless city or a busy airport – may also impact your brain.
A study in Europe shows that residing in a noisy locale bumps up your chances of eventually having memory problems. And these researchers say their study shows that noise combined with air pollution has an especially damaging effect on the brain .3
The big takeaway from these findings is to go out of your way to protect your ears and hearing, because when you protect your ears you’re also protecting your brain. You should keep the volume down on your music. Wear ear protection when attending loud concerts. Your ability to hear clearly is crucial for keeping your brain healthy.