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| EAR DISORDERS & TREATMENTS > Noise and Your Hearing |
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NOISE AND YOUR HEARING
Can noise damage your hearing?
Every day we experience sounds in our environment such as the television,
radio, washing machine, cars, music, and trucks. When you are exposed to harmful
sounds, such as sounds that are too loud or loud sounds over a long time, the
sensitive structures of the inner ear can be damaged, causing a hearing loss.
Noise-induced hearing loss (NIHL) is the diminished hearing ability that occurs
as a result of the damage to the inner ear by these harmful sounds. The noise
damages the hearing cells of the hearing organ (cochlea) in the inner ear.
How much noise is too much?
Both the loudness of sound (called the intensity) and the amount of time you hear
the noise will determine your risk of hearing damage. The loudness of sound is
measured in decibels (dB). The hearing cells in your inner ear can tolerate no more
than 85dB of sound for 8 hours before permanent damage starts to occur. At higher
sound levels, you could lose hearing in even less time, because every 3dB increase
in sound halves the amount of time the ear can tolerate sound before damage occurs.
Sounds of 100dB can cause damage in just over 15 minutes and sounds of 103dB in just
7 minutes 30 seconds!
The table below provides a guideline of the sound level in dB which is measured for
some typical listening environments. For example, if you are riding a motorcycle,
you receive an average loudness of 95dB, which means that if you ride an unsilenced
motorcycle without hearing protection for over one hour, you risk noise damage.
Keep in mind that the hair cells can also be permanently damaged from a sudden or
one-off exposure of 130-140dB or above. This might occur from gunfire close to the
ear or a blast injury. This kind of sudden damage is called acoustic trauma.
The following table shows the safe limits for common noises:
| Level in decibels (dB) |
Noise |
Exposure time |
| 140 - 150 |
Firecracker, gunshot, jet engine |
No safe exposure at this level. Acoustic trauma may occur. |
| 120 - 130 |
Ambulance siren, car horn |
Less than 7 seconds of exposure. Risk of acoustic trauma starts at this level. |
| 110 |
Rock concert, nightclub |
Levels can range from 95-130dB, but concerts are often at 110dB, depending on distance from the speakers. At this level, exposure of more than 1 minute risks permanent hearing loss. |
| 105 |
Personal stereo at maximum volume, amplified rock music |
Levels can range from 105-130dB. At these levels it is less than 2 minutes before damage begins to occur. |
| 100 |
Chainsaw, Jackhammer, Wood-working area |
No more than 15 minutes unprotected exposure recommended. |
| 95 |
Motorcyle |
Unprotected exposure for over 1 hour could result in noise damage. |
| 90 |
Lawn mower, workshop tools |
Exposure for longer than 2 hours and damage may occur if no hearing protection is worn. |
| 85 |
Heavy city traffic, average factory |
Prolonged exposure of over 8hrs a day can cause gradual hearing loss. |
| 70 |
Vacuum cleaner, noisy restaurant |
Considered within safe limits for prolonged exposure of over 16 hours a day. |
| 60 |
Normal conversation |
Considered within safe limits. |
| 40 |
Refrigerator humming |
Considered within safe limits. |
| 30 |
Whispered voice |
Considered within safe limits. |
In 2005, researchers from the Ear Science Institute Australia (ESIA) and Ear Sciences
Centre at The University of Western Australia, measured sound levels in twelve popular
entertainment venues in Perth, Western Australia. To review the findings, Click Below
How common is noise induced hearing loss?
Noise induced hearing loss is the second most common type of hearing loss after
presbyacusis (old age associated hearing loss), and all age groups can be affected.
There is a slight male bias, but it is still unknown if this is a result of occupational
status (such as working with heavy machinery) or an increased vulnerability to NIHL.
Studies show that deafness from noise exposure at work (often termed industrial deafness)
is a serious community problem. For example, a study of the farming industry in Australia
indicated that over two-thirds of farmers had hearing loss attributable to noise exposure.
Researchers are now predicting an increase in recreational noise induced hearing loss with
the increase in use of personal stereos at excessively amplified levels.
How can I tell if noise has damaged my hearing?
Noise damage can be temporary or permanent, and you may not recognise damage to your hearing
immediately.
Temporary hearing loss is recognised as a change in your hearing after a few hours in a
loud environment, such as a concert. Typically this is a dullness in hearing that recovers
over time and is termed temporary threshold shift. You are also likely to notice tinnitus
(ringing in the ears) immediately after the noise exposure. Temporary damage occurs due to
fatigue of the hair cells. If the hair cells recover, then the damage was deemed temporary.
If the sound exposure was excessive then the cells don't recover and permanent noise damage
results.
Permanent threshold shift is often not detected until 48 hours after the exposure and can become
increasingly worse for a number of years after the original damage occurred. Typical symptoms
reported by those with a hearing loss is that sounds become distorted or muffled, and that it is
difficult to understand speech on the telephone, television or in situations with background
noise. Aside from the loss of hearing acuity, permanent noise damage can also result in permanent
tinnitus, which can be distressing and reduce your overall quality of life.
Keep in mind that noise-induced hearing loss is often gradual, and that you may only lose your
ability to hear high-pitched sounds at first. If you have any concerns that you may have noise
induced hearing loss, you should have a comprehensive hearing test with an audiologist.
What can I do to protect my hearing?
Hearing loss from noise exposure is preventable. All individuals should understand the hazards of
noise and know how to protect their ears:
1. Be familiar with the kinds of activities that could damage your hearing and the maximum
amount of time you can be exposed to these activities before permanent damage occurs.
2. Avoid or modify those situations where noise is at dangerous levels. For example, don't
stand too close to the speakers at concerts, don't stand in the vicinity of people using noisy
machinery, spend less time in noisier environments, turn down your ipod or personal stereo or
consider purchasing quieter machines in a noisy workplace. For more information on noise control measures,
particularly in the workplace, Click Below.
3. If there are no alternatives to reducing the noise level in your environment, wear
earplugs or other hearing protective devices when involved in a loud activity. For more information on earplugs and
earmuffs, Click Below.
4. Have a hearing test by an audiologist, who is a health professional trained to identify
and measure hearing loss and to rehabilitate persons with hearing impairments.
What can I do if I already have noise damage?
Damage to the hair cells of the inner ear is irreversible, so permanent noise induced hearing loss
will not improve on its own. Listening devices such as hearing aids will help to increase the volume
of those sounds that you have problems hearing, but they will not improve your permanent hearing levels.
Remember that if you already suffer from a degree of hearing loss it is imperative that you protect your
residual hearing by following the noise protection guidelines above.
The information contained on this page is not meant to be a substitute for the advice from
a surgeon or other clinical specialist. This is not a complete discussion of ear disease and is not a
complete explanation of the risks of surgery and/or treatments.
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