The human ear is a complex and delicate organ. Although it does help the body stay in balance, its primary job is to detect and amplify sounds. Unfortunately, loud noises in the environment can damage sensitive ear structures, which can lead to temporary and even permanent hearing loss.
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Your ear works by catching sound waves in your environment and translating them into signals your brain can interpret. Sound waves travel through the ear canal to the eardrum, causing it to vibrate. The eardrum's vibrations travel to three tiny bones in the middle ear, which amplify them and send them to a snail's shell-shaped structure called the cochlea. This is a hollow structure with fluid-filled canals. The cochlea is filled with a special fluid that sits under an elastic membrane called the basilar membrane. Sound vibrations from the middle ear cause ripples in the cochlear fluid, which make the basilar undulate. Sensory hair cells on top of the basilar move along with it, creating electrical signals that are picked up by the auditory nerve and sent to the brain.
The most common cause of hearing loss is age, followed closely by internal damage due to exposure to loud noise. Sudden noises, such as an explosion, a gunshot or a firecracker, can cause immediate hearing loss, which can be temporary or permanent. Also, sustained exposure to moderately loud noises, such as lawnmowers, power tools or loud music, can cause cumulative and progressive hearing loss.
Harmful Noise Effects
Prolonged exposure to loud noise slowly damages the hair cells -- sensory receptors for sound and body position-- that line the ear's basilar. The cells send information to the brain through the cochlear nerve. Once damaged, these cells do not regenerate. Loud noises can also damage the cochlear nerve and impede it from sending auditory signals to the brain. According to the National Institute on Deafness and Other Communication Disorders (NIDCD), noises at or below 75 decibels are generally considered safe, even with long-term exposure. However, prolonged exposure to 85 decibels or above can cause ear damage.
To put this in perspective, the sound of normal conversation is about 60 decibels, heavy traffic is about 85 decibels, your lawnmower is abut 90 decibels and firecrackers, gunshots and rock concerts range from 110 to 150 decibels.
If you have to raise your voice to be heard, you can't hear someone two feet away from you, or sounds seem muffled or dull after leaving a noisy environment, the noise around you is at a potentially hazardous level. Other signs of hazardous noise exposure include ear pain and tinnitus, or ringing in the ears. If you feel that your ears have become accustomed to loud noises, you may already have experienced hearing damage. Many people are not aware of hearing damage until they are tested.
Preventing ear damage due to noise is possible. If you work in a noisy environment, wear protective earplugs or noise reduction headphones while you work. You should also wear earplugs while mowing the lawn, using loud power tools or attending a concert. You can protect your children's hearing by limiting their use of loud toys and ensuring that the volume is low on the electronic devices they use.