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A man cups his ear.

The two most common causes of hearing loss are noise and aging, and it's kind of hard to avoid either.

But there are many things we can do to forestall hearing loss.

In most cases, hearing loss is the result of damage to nerve cells in the inner ear. Continuous exposure to loud noises over a lifetime and the gradual changes in our bodies as we age cause wear and tear that's permanent, though researchers are testing theories and studying animals that have the ability to regenerate the receptors in the inner ear.

In fact, researchers seeking answers to hearing loss prevention are spending as much time studying the brain as they are the inner ear. And the conclusion they're drawing is that we need to help our brains keep listening by paying immediate attention to any signs of hearing loss.

Nothing, though, takes the place of protecting yourself when you're in a noisy environment. Sound waves flow over receptor cells in the ear like wind blowing over a wheat field. Blasts of noise can level swaths of these cells by essentially overloading them. It used to be the workplace, such as factories and farms, that contributed to such noise pollution, but for boomers - the first generation raised on concerts, lawnmowers and headphones - leisure pastimes and other environmental factors have done damage, as well. While it's common knowledge today that it's a good idea to wear earplugs when you're using a circle saw on the new deck or to keep the Rolling Stones at a respectable volume as you bomb down the highway, audiologists say people still abuse their ears.

The effects of losing your hearing - the potential of becoming withdrawn from family, friends and social situations - should be motivation enough to take precautions. But researchers are also discovering connections between hearing loss and brain disorders such as dementia.

Kathy Pichora-Fuller, a professor of psychology at the University of Toronto and an audiologist, says when it comes to age-related neural degeneration, the auditory system may be the canary in coal mine.

"We don't know why there is a connection, but there are ideas," says Dr. Pichora-Fuller, who studies the intricate relationship between the ear and the brain - a unique field that combines experience in rehabilitative audiology with experimental research on auditory and cognitive aging.

"The auditory system does these exquisite analyses in fractions of milliseconds in order for you to know where a sound is and what it is. So if the neurons are firing in a very precisely timed fashion, where you're going to notice that it's not quite what it used to be could be the auditory system first."

One of the things researchers are studying is how the brain adapts to gradual hearing loss, and what they're discovering is that even in old age, your brain can rewire itself. Studies have shown, for example, that older people are very proficient at using context to compensate for hearing loss, essentially figuring out what a noise is based on what's happening around them.

But that sort of learned behaviour relies on extrapolation. In order to teach the brain how to keep listening, researchers believe early detection and the use of a hearing aid can actually decrease the rate of hearing loss.

"The brain, even into old age, is very plastic," says Dr. Pichora-Fuller. "It can rewire. There's a lot a of research about … training your brain to keep it healthy. If you have an appropriate amount of listening exercise, it will rewire itself."

The problem with that is, of course, our penchant for ignoring things such as hearing loss until it has become severe. By all logic, it's wise to start using a hearing aid as early as possible, rather than coping with it by avoiding social situations. However, that requires people to get over the social stigma of wearing a hearing aid.

"What I would like to see is hearing to be part of the bigger picture," says Dr. Pichora-Fuller. "Mental exercise, physical exercise, social exercise - all of these things keep your brain healthy. If you withdraw from social interaction because it's difficult to hear, you're basically on a slippery slope."

PREVENTION TIPS

Avoid loud noise: Whether at home or work, try to avoid loud noises. If that's not possible, wear some type of ear protection. Don't blast tunes through your headphones.

Avoid smoking: Researchers in Belgium have shown there's a connection between hearing loss and smoking because smoking can disrupt the flow of blood around the body, including to the inner ear.

Apps: There are several smart phone apps available that can help diagnose early hearing loss, including Uhear

COMMON NOISES

More than 1 minute of constant noise at 110 decibels can cause permanent damage

Rock concerts, Firecrackers - 140 decibels

Snowmobile - 120 decibels

Chainsaw - 110 decibels

Wood shop - 100 decibels

Lawnmower, motorcycle - 90 decibels

Prolonged exposure to any noise above 90 decibels can cause gradual hearing loss

City traffic noise - 80 decibels

Normal conversation - 60 decibels

Refrigerator humming - 40 decibels

Whispered voice - 20 decibels

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