Most of us would guess that a sudden, extremely loud noise could damage our hearing. But did you know that sounds that are not quite so ‘deafening’ can be equally damaging if they go on for some time?

How does loud noise damage hearing?

Sound is collected by the outer, visible part of the ear, and channeled down the ear canal towards the eardrum. The very thin skin of the eardrum vibrates, which passes this vibration to a chain of three tiny bones – the smallest in the body – on the inner side of the ear drum. These bones move with the eardrum, and pass the sound on to the inner ear, also known as the cochlea. The cochlea is lined with minute hairs that send electrical signals to the brain which can then interpret what we are hearing. These ‘hair cells’ are very delicate, and can be damaged or destroyed by sudden intense noises, like a firecracker or an explosion, or by continuous and/or repeated exposure to high levels of noise. Unfortunately, once these hair cells are damaged, they are gone for good – they do not re-grow, and there is no medical treatment that can repair them.

So how loud is too loud?

Noise levels are measured in decibels, or dB for short. The higher the number, the louder the noise. Sounds louder than 85 dB can cause permanent hearing loss.

There are the obvious unpleasant sounds that we all try to avoid:

• 150 dB = fireworks at 3 feet
• 130 dB = jackhammer
• 120 dB = jet plane takeoff, siren

But there are other sounds too, not so obviously unpleasant, but that we can run into almost daily:

• 110 dB = chain saw
• 106 dB = gas lawn mower
• 100 dB = hand drill, pneumatic drill
• 90 dB = subway, passing motorcycle
• 80–90 dB = hair-dryer, kitchen blender, food processor
• 70 dB = busy traffic, vacuum cleaner, alarm clock

And, of course, we sometimes choose to expose ourselves to sounds at potentially dangerous noise levels: Did you know that the maximum output of some MP3 players can reach 110 dB?! Compare that to the noise level of a chain saw…

But I don’t carry a noise meter; how can I tell if a noise level is dangerous?

Unfortunately, children may not realize the long-term dangers of noise, and the youngest kids can’t really control their own exposure anyway. It is up to us, as parents and responsible adults, to help educate older children to take better care of their hearing, and to limit what we expose our youngest children to.

The obvious first rule is to avoid loud noise whenever possible. A good rule of thumb is to remember that if you must shout to be heard, then you should avoid the situation. A noise is too loud if you cannot hear someone 3 feet away from you.

How can I protect my child’s hearing from loud noise?

Sometimes we just cannot avoid hearing loud noises: Fire trucks pass us on the road; there may be construction in the street outside; we spend hours on noisy airplanes… And, of course, we sometimes expose ourselves by choice: we go to concerts, loud parties, and sports events; we listen to our stereos or iPods cranked up way too far… What can we do to limit the chance of damaging our hearing or the hearing of our children?

• An obvious one: Encourage your children to keep the sound level set to no more than half volume. If you can hear the music from a pair of headphones, it is almost certainly too loud for the person wearing them.

Or, when you know that you will be exposed to a noise level outside your control:

• Wear hearing protection: Earmuffs or earplugs can be purchased at drugstores, hardware stores, or sports stores. Earplugs are placed into the ear canal so that they totally block the canal. They come in different shapes and sizes, and can reduce noise by 15 to 30 decibels (dB) depending on how they are made and fit. Earmuffs fit completely over both ears. They must fit tightly so that sound is blocked from entering the ears. Like earplugs, muffs can reduce noise 15 to 30 dB depending on how they are made and fit. Earplugs and earmuffs can be used together to achieve even greater sound reduction. Use of earplugs and earmuffs is recommended when noise exposure is particularly high. As a last resort, you can even plug your ears with your fingers – it’s better than nothing!

• Be a good consumer: Look for noise ratings on appliances, sporting equipment, power tools, and hair dryers. Purchase quieter products. This is especially important when purchasing toys that make sounds.

• Speak out: Don’t be afraid to ask others to turn down the sounds from speakers. Speak to the movie theater projectionist if the movie soundtrack is too loud. Talk to the manager if the music at the bouncy castle place is deafening.

• Be a local advocate: Some movie theaters, health clubs, party venues, and amusement centers are very noisy. Speak to managers and those in charge about the loud noise and the potential damages to hearing. Ask to have the noise source lowered.

Can’t my ears just get used to noise?

Don’t be fooled by thinking your ears are “tough” or that you have the ability to “tune it out”! Noise-induced hearing loss is usually gradual and painless but, unfortunately, permanent. Once destroyed, the hearing nerve and its sensory nerve cells do not repair.

If you think you have “gotten used to” the noise you routinely encounter, you may already have some hearing damage.

To learn more about Noise-Induced Hearing Loss, tune into the podcast at:

https://dmr.homefrontdc.com/272/may-is-better-hearing-and-speech-month/

But don’t forget to keep the volume down!