Ringing ears may recover but nervous system doesn't, says audiologist

Your ears might ring for a few days after a concert and recover, but an audiologist says the signs of damage are seen in the auditory nervous system.

"We tend to hear sound with our ears but we listen to our brain," audiologist Calvin Staples told CBC News.

Our auditory nervous system interprets the sound signals sent by hair cells in our ears.

Roughly 16,000 hair cells in our ears detect sound. When exposed to very loud noises, they can become damaged.

Staples compared it to blades of grass becoming matted down when people step on them.

"Those hair cells may recover, but the damage going up the auditory nerve and at higher levels of the auditory system, they don't think it does recover," he said.

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People with a damaged auditory system have a hard time listening in complex environments where there are many layers of sound, such as in a restaurant.

"I feel like we're seeing more and more younger adults in their thirtiesand forties coming into the clinic saying 'I just can't hear, I just can't hear as well as I used to,' yet they still might pass their hearing test," Staples said.

Everyday living too loud

Even activities like mowing the lawn and commuting can be fairly noisy. For example, bus rides can have many loud conversations in addition to street traffic and engine sounds.

Staples said people who listen to music may turn up the volume in their headphones to combat the noise. However, they might not realize the levels are too loud.

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In May the Toronto's medical officer of health published a report on the harmful effects of Toronto's environmental noise on cardiovascular and mental health.

Municipalities outside of Toronto are less dense and may not have the same level of construction and traffic noise. However, the report may still concern you if you're constantly near construction zones or work in loud environments.

The National Institute for Occupational Safety and Health at the Centers for Disease Control and Prevention says that people can be exposed to 85 decibels of sound for eight hours before suffering damage. Busy city traffic is measured at around that level.

The safe exposure time limit decreases in half with every increase of three to five decibels. At concerts you may only have minutes of exposure before your ears are damaged.

Hearing loss and senior isolation

Staples mentioned that hearing loss can affect someone's quality of life. One example is tinnitus, which can't be cured, only managed.

"It has been noted that a lot of tinnitus folks are quite stressed by their lack of control over their tinnitus," he said.

Hearing loss is also a cause of isolation.

He said because a lot of human interaction is still done through speaking and listening, socializing is difficult when older adults can't hear as well as they used to.

Staples said that while hearing aids are very effective, some people give up when their first pair doesn't work.

"It's unfortunate because when hearing aids are done correctly, hearing aids work really well for most people," he said. "If you can steal from Helen Keller, blindness separates us from things, but deafness takes us away from people."

Use protection and start young

Staples suggested ear plugs as the best method of protection.

However, he warns that over-the-counter foam ear plugs are not effective unless they're inserted deep into the ear, because sound can slip through spaces.

"If you can see them, they're probably not providing much help," he told Craig Norris, host of The Morning Edition on CBC Radio.

People can also opt for custom ear plugs or ones with filters specifically made for listening to music.

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Staples also said people should check their hearingstarting in theirforties unless you encounter hearing problems earlier.

"The ability to hear is so important, but because it rarely poses a direct safety concern, people don't look at knocking hearing off the list as something to get checked," he said.