Hear Today, Gone Tomorrow

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WORDS Catherine Kwok & Amanda Moore

Audiology students explain noise-induced hearing loss (NIHL) and how you can protect your hearing.

The (insert-band-name) gig was over hours ago. Your wrist stamp is smudged and beginning to fade. So why does it feel like the band is still playing in your ears?

Hearing sounds that torment your ears long after the band has finished is called tinnitus (not to be confused with the unsightly foot disease, tinea). Tinnitus is a sound in the ears that happens when no sound is present. It can be a ringing, rushing, roaring or hissing noise and occurs in more than 60 per cent of young Australians after listening to loud music.

If you are listening to your iPod with the volume too loud or are standing too close to the speakers at a gig, you may be putting yourself at risk of developing a noise-induced hearing loss (NIHL). The likelihood of NIHL depends on how loud the sound is and how long you are exposed to it. It can occur from an intensely loud sound once, like an explosion, or exposure to a reasonably loud sound over a period of time, such as a band playing or your iPod volume being too loud.

First, you experience a temporary threshold shift, where your hearing threshold is raised and you don’t hear as well as you normally would. This can last from 16 to 28 hours after the noise exposure; your hearing then recovers. However, after repeated exposures to loud sounds, this temporary condition can become a permanent one. This is when your hearing becomes worse and never improves. This is the second most common cause of permanent hearing loss (after hearing loss due to old age).

Why does this happen?

Inside your inner ear are hair cells that move in response to sound vibrations. As they move, they send electrical impulses along your auditory nerve to your brain. When you listen to loud sounds, these hair cells become can bent and damaged. This damage is permanent!

How do you know if you have a noise-induced hearing loss?

Tinnitus is one warning sign that you have NIHL. Another sign is that sounds may seem distorted. Speech may be muffled and difficult to understand. You may find it hard to follow a conversation when there is background noise, such as in a café or restaurant. Game of Thrones becomes even more difficult to follow.

How do you prevent NIHL?

Remember when your parents told you to turn your music down? It turns out there was a reason. Who’d have thought?
When you listen to your personal music player at over 100dB, it only takes 15 minutes for you to suffer from permanent damage. A good rule of thumb for iPod use is the 80/90 rule: 80 per cent of the maximum volume for no more than 90 minutes a day. Just to be sure, you might want to consider using the volume limiting software on your iPod or MP3.

Another hint is when you are listening to your iPod on the bus or train, be aware that you don’t keep turning up the volume to drown out the background noise.

Sitting or standing right near the speakers at a music concert can expose you to sounds over 120dB, which will cause you hearing damage in less than eight minutes. Try not to stand within two metres of the speakers to avoid putting your hearing at risk. When you go to a club, wear ear plugs or take an occasional break from the music. Walking away from the sound source is the simplest, cheapest and most effective way of preventing hearing loss.

It’s not just sound engineers and musicians that need to wear ear plugs. Regular punters at a music venue can also benefit. Ear protection decreases the intensity of noise and helps protect your hearing. It should be worn when exposed to sounds louder than 85 decibels for a long period of time.

The take home message is that noise-induced hearing loss is forever, like that tattoo of the Asian water sign you got on your last holiday. It’s also cumulative: the longer you are exposed to the loud sounds the more damage you are potentially doing.

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How to Save Your Hearing

FOAM INSERTS– these fit into the ear and block out noise. They are available at pharmacies and hardware stores. They are cheap and are often effective for one use only. The limitation is that they reduce high frequency sound which can make it hard to hear speech while wearing them.

NOISE CANCELLATION HEADPHONES OR BUDS– these reduce the noise around you and make it less likely that you will increase volume to drown out outside noise.

SILICON CUSTOM FIT MOULDS– to give reduction equally across all frequencies. These are fit to your ear and they last longer, however they are more expensive.

MUSICIAN EAR PLUGS– that fit the ears well. They give a flat attenuation (noise reduction) of 9-25dB. Also noise cancelling headphones can be used.

ELECTRONIC EARPLUGS– These reduce the loud sounds more than the soft sounds. Some may even amplify the soft sounds by including a speaker and microphone in the earplug.

Finally, the important thing to remember about noise induced hearing loss is that it is 100 per cent preventable. You can still be a groupie and keep your hearing. There are a few things you can do to ensure that you will be able to download your music and hear it too. Protect yourself from loud sounds and on Conception Day look out for people from the Australian Hearing Hub handing out ear plugs.