Valuable and irreplaceable hearing cells
The cochlea, the organ of hearing, has only around 15,000 cells—far fewer than the millions of cells in our eyes. And these precious few cells can’t be regenerated—another reason why you should take steps now to protect them!
Can noise cause hearing loss?
Our hearing helps us make sense of the world around us. However, our auditory system is highly sensitive to loud noise, and frequent exposure to noise can gradually lead to hearing loss over time. But you can protect yourself!
Sound, it’s all about good vibrations
Sounds travel in the form of sound waves, which are simply changes in atmospheric pressure. The sounds we hear are characterized by :
– Frequency in Hertz (Hz) – The human ear can hear frequencies ranging from 16 Hz (the lowest-pitched frequency) to 20,000 Hz (the highest-pitched frequency);
– Loudnessin decibels (dB) – Loudness can range from barely audible to painful to the ear; and
Sound waves enter the outer ear canal and strike against the eardrum, causing it to vibrate. This vibration then causes the inner ear to vibrate, passing the vibrations to the cochlea, the organ of hearing. Cells in the cochlea convert the acoustic energy (vibrations) into nerve impulses that are transmitted by the cochlear nerve to the brain.
Noise: The enemy around us
Are you exposed to dangerously high noise levels?
Yes if :
– You can’t carry on a conversation with someone a meter away without raising your voice.
– A driver in another car can hear your car radio even though his windows are closed.
– Other train or subway passengers can hear the music from your headphones.
Sound becomes noise when it is bothersome or damaging to our auditory system. Few sounds in nature are noise, but in our modern society we are frequently bombarded by noise of all kinds. And our ears have not evolved to effectively shield out the harmful effects of noise.
Noise becomes dangerous when its loudness in decibels (dB) exceeds 85 dB, the level which our ears can handle :
– Below 85 dB, there is little risk of hearing damage. This is roughly the loudness of a vacuum cleaner or someone snoring, for example.
– Above 85 dB, the noise becomes damaging — and the higher you go, the more damaging it becomes. The noise in a night club often reaches nearly 100 dB.
Why does it matter? Because frequent exposure to loud noise can cause auditory fatigue, tinnitus, permanent auditory trauma, or even eardrum rupture.
The danger threshold
Eardrums can be ruptured by impulse noise, which is an extremely dangerous burst of acoustic energy. Impulse noise often comes from pure, high-frequency sounds like those of an alarm being tested or a firearm going off. These noises can rupture the tympanic membrane immediately, which causes sharp, intense pain. The resulting deafness can be permanent.
Auditory trauma is caused by exposure to loud noise (over 85 dB for 8 hours in a row), either once or repeatedly. It results in permanent damage to the cochlea because it destroys the cochlea’s hair cells. Auditory trauma eventually leads to deafness. It can also lead to tinnitus (ringing, buzzing, or drumming sounds in the ear).
Very low frequencies can mask high frequencies and make them difficult to hear (for example, the difficulty we sometimes have hearing someone speaking in a noisy room). This masking effect makes it almost impossible to hold a conversation in a noisy environment. The immediate consequence is fatigue, which can be especially dangerous in an industrial workplace because it causes distraction and difficulty concentrating.
Auditory fatigue is a temporary reduction in hearing ability, often accompanied by a ringing or buzzing in the ear. It typically occurs after prolonged exposure to loud noise (above 60 dB). Auditory fatigue will disappear after resting in a quiet environment.
|An airplane taking off at 100 meters||< 1min||130|
|Standing next to the speakers at a concert||1 min||120|
|The legal noise limit for nightclubs||45 min||105|
|A car horn or jackhammer at 2 meters||2 h||100|
|Earphones at high volume or police siren||7 h||95|
|Barking dog or lawnmower||20 h||90|
|School cafeteria||40 h||85|
|High-traffic street or vacuum cleaner||80|
|Noisy classroom or snoring||70|
|Busy market or computer printer||60|
|Watch ticking or light breeze blowing through trees||20|
|Leaves rustling or the desert||10|
|Audibility threshold in an acoustics lab||0|
Protect your hearing
– Keep the volume of your stereo, car radio, or portable audio device at a reasonable level.
– Don’t listen to music with headphones for more than one hour a day.
– Take a 10-minute break in a silent environment every hour.
– Let your ears rest for at least 12 hours after a concert or evening at a night club.
We also suggest you use earplugs if you know you will be exposed to loud noise. Today’s earplugs offer effective protection and are comfortable and discreet.