Noise Protection and Hearing
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Originally Posted On: https://ed.ted.com/on/l2SYJpID#digdeeper
If you work in a noisy environment it’s important to protect your hearing. You can do this by using earplugs or headphones that block out the noise sufficiently. If your job exposes you to high levels of noise on a regular basis, it’s even more important that you understand how to protect your hearing.
Some people think they’re doing the right thing by wearing hearing protection such as ear defenders or plugs but they’re not, because the only effective way to protect your hearing is to wear both correctly.
Ear defenders are designed to reduce noise levels by about 15dB, which means that if you work in an environment where the level of noise is 100dB(A), you can still be subjected to 85dB(A). Ear plugs are designed to block out the noise and they do this very effectively – using earplugs reduces noise levels anywhere from 12 – 30 dB(depending on how well they fit) so if you’re working with a source of noise at 100dB(A), wearing earplugs allows levels inside your ears to drop down below 70 dB (the safe limit for any one day is 80dB). Wearing just one or the other doesn’t really do the job.
This is because most noise environments are not ‘pure tones’ (a single frequency with no harmonics or overtones) with sources like jet engines, saws and sanders all having harmonic content that ear defenders will do nothing to suppress. , for example, can go up to about 120dB(A), but when it has gone through the blades on its wayout of the engine its sound is spread out over 5 different frequencies while a still fairly loud 100dB(A) engine might have 350 components per second! This means that if you wear hearing protection in some form, it’s best to have some sort of idea of how much noise you are being subjected to so that you know what your exposure levels are.
You should speak to an audiologist if you have any doubts about how you should protect your hearing.
Noise-induced hearing loss (NIHL) is caused by damage to the microscopic endings of the nerve that pick up sound vibrations in your ear or damage to the nerve itself. When this happens, you lose some of your ability to hear high-pitched sounds. If unwanted noise isn’t blocked out, you’re at risk of developing NIHL over time.
If you’ve already lost some of your ability to hear high-pitched sounds due to noise damage, it’s called ‘hidden hearing loss’. You might not realise this – so ask yourself if other people have commented on your hearing recently? If they have, ask yourself what changes there have been in your life since these comments started – do you work more with noisy equipment or have noisy hobbies?
If you think you have hidden hearing loss, it’s best to be checked by a GP or audiologist. They can look for signs of noise damage and advise on any protection that may help. Hearing aids are also available which improve the clarity of sounds and reduce the risk of hidden hearing loss.
These two types of NIHL – temporary threshold shift and permanent threshold shift – usually recover in hours or days after exposure to loud noise ends. That’s because it takes time for your ears to readjust to normal levels, just like how it takes time for eyesight to readjust when bright light is shone into them. However, if your ears do not adjust back well enough, this is when your hearing will be damaged permanently.
People spend a lot of time listening to music with earphones or headphones, especially young people. Music listened to through these devices can often be listened to at high volumes. Losing awareness about the volume level means that permanent damage to your hearing could occur without you even realising it was happening . Using common sense is an easy way to make sure you don’t cause yourself any damage.