Hey! Can you hear me? - How to protect your hearing health
Tuesday 22 August 2017
According to Hearing Awareness Week, one in four Australians will have some form of hearing impairment by 2050.
That’s a lot of people turning the TV volume way up and asking others to repeat what they’ve said.
As well as our aging population, rising rates of hearing loss can be attributed to our noisy lifestyles. With loud concerts, music blaring through earphones and noisy workplaces, noise injury is a major, and preventable, cause of hearing loss.
Read on to find out how hearing works, how noise can destroy your hearing and what you can do to protect your ears.
How hearing works
Hearing is a pretty complex process that involves a number of different parts of your ears.
As sound waves move through the air they hit your eardrum, causing it to vibrate. These vibrations then travel to three small bones inside your middle ear, called ossicles, which make the vibrations bigger. The vibrations are then passed into your inner ear, which contains a complex organ of fluid and hair cells called the cochlear. The vibrations cause the fluid to move and the tiny hair cells detect the movement, signalling the auditory nerve that passes the sound information to your brain.
Different sounds have different wave frequencies. A high pitched sound, like a mouse’s squeak, has a high frequency, while a deep sound, like a bear’s growl, has a lower frequency. Different groups of the hairs in your cochlear are responsible for detecting different frequencies.
What is hearing loss?
Hearing loss can occur in three different ways.
Conductive hearing loss: which means sound can’t get through from your outer ear to your inner ear. This is often caused by some kind of blockage, like earwax, an ear infection or damaged ossicles. This type of hearing loss can be temporary or permanent.
Sensorineural hearing loss: where the tiny hairs inside your cochlear are damaged. Some or all of the hairs may be affected. You can be born with this hearing loss, or you may acquire this type hearing loss due to inherited genetic traits, noise injury, infections or head injury. Noise injury can cause irreversible damage, but it can be preventable.
Thirdly, it’s possible to have mixed hearing loss, or both conductive and sensorineural hearing loss at the same time.
How much noise can damage your hearing?
Most people know that loud noises can damage your hearing. But it’s not all about volume; the length of time you’re impacted by a noise plays a big part in how damaging it can be, as does how often you hear it.
When a particular sound hits the hair cells in your cochlear too loud, or for too long, they can be damaged and die. Unlike many other parts of the human body, these hair cells can’t regenerate. If you lose the hair cells that were responsible for picking up a particular frequency, then you will no longer be able to hear that sound.
Sound intensity is measured in decibels (dB). Loud noises are 90dB or more: chainsaws, nightclubs and motorcycles all measure above 90dB. After one hour of listening, exposure to noise level at 90dB can begin to cause damage without ear protection.
Really loud sounds that measure over 120dB, like ambulance sirens or jet planes taking off, should be avoided without proper hearing protection, as these can damage your hearing immediately within 15 minutes.
Cumulative noise exposure to loud noise in leisure activities such as clubbing, listening to loud music and dance parties for more than the maximum allowable noise dose is a risk for developing a hearing loss.
But what about more moderate sounds? Sounds between 70 and 90 decibels may warrant ear protection if you’re going to listen to them for a while.
A coffee grinder clocks in 80dB, which you can safely be exposed to without ear protection for 8 hours. But if you’re a barista pulling a long shift, this sound could get dangerous.
A hair dryer is about 75dB and hair clippers 72dB. Both of these are also safe for up to 8 hours, so hairdressers and barbers should watch their timesheets.
If you’re using earphones with a music device, the sound should be about 80dB, as long as you don’t have it up as loud as possible (60% of the maximum range is safe with earphones). Having well-fitting earphones or headphones is important: if outside sound leaks in you might be tempted to turn the volume right up to drown it out, bombarding your ears with higher decibels.
Lower sounds, between 0 and 70 decibels, are considered safe. Talking voices average 62dB, your computer 44dB, dishwasher 68dB and fridge 58dB.
You can find out the average decibel level of different sounds on the Hearing Awareness Week website, as well as recommendations about when ear protection should be used.
How to protect your ears and save your hearing
Hearing loss can come naturally with age, but there’s a lot you can do to protect your ears throughout life.
Protection is prevention: wear earplugs or earmuffs whenever you’re doing anything that involves sustained or loud sound like:
- night clubs and dance parties
- playing in a band
- seeing a concert or attending a festival
- using mechanical equipment like a drill or chainsaw
- or working in a noisy environment or around machinery, like at a farm, factory or construction site.
Make sure your earbuds or headphones fit and work well, so you’re not turning your music up too high. Use the 60/60 rule – only turn your music device up to 60% of its total volume and listen for no more than 60 minutes per day. Good listening habits now may mean that you can continue to enjoy listening to music now as well as in decades to come.
Take breaks after being exposed to noise, to give your ears a chance to rest.
Remember that just because a noise isn’t annoying, doesn’t mean it might not be dangerous over a long period of time. It might not feel too loud, but a sustained sound can be just as damaging to your ears as a loud one.