With Independence Day coming up, many of us are looking forward to backyard barbecues, parades, concerts and fireworks. During the many activities that come with the holiday, it’s important to also take steps to protect our hearing while we enjoy ourselves.
Noise is one of the most common causes of hearing loss and can impact people of any age. Hearing loss can result from a single exceptionally loud noise, or from repeated exposure to noise levels. In normal hearing, sound waves enter the outer ear and travel down the ear canal to vibrate the ear drum. Those vibrations activate tiny bones in the middle ear that trigger fluid vibrations in the cochlea, the sensory organ of hearing. Those vibrations move microscopic hair cells in the cochlea that create electrical signals that travel to the brain, which recognizes the signals as sound.
Noise exposure can damage the hair cells in the cochlea. When sound vibrations are too large, the fluid motion in the cochlea can bend hair cells to the point of breaking. Since those hair cells cannot grow back, noise-induced hearing loss cannot be reversed. Fortunately, noise-induced hearing loss can be prevented.
Earplugs or other protective devices like ear muffs can help when you are watching fireworks or attending a concert. If you find yourself in a dangerously loud environment without ear protection, try to move away from the source of the noise; for instance, by standing behind a speaker instead of in front of it. Be sure to protect children’s ears as well, since sound is further amplified within smaller ear canals.
The louder the sound, the more damage it can cause, and the faster that damage can occur. But how do you know how loud is too loud? Sound is measured in units called decibels (dB). Researchers have found that people who are exposed to noise levels at or above 85 dB have a much greater risk of hearing loss.* A whisper is about 30 dB, normal conversation occurs around 60 dB, and city traffic is about 90 dB. If you find yourself having to raise your voice to communicate with someone a few feet away, the noise level is probably above 85 dB. Some smartphone apps can also measure the surrounding decibel level.
Don’t sacrifice your hearing while you’re having fun. This July 4th, protect your ears while you’re enjoying the festivities!
*M Moselhi et al. “A six-year follow up study for evaluation of the 85 dBA safe criterion for noise exposure” American Industrial Hygiene Association Journal 40:5, published online June 4, 2010.
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