What causes it?
Sounds of sufficient intensity and duration will damage the ear and result in temporary or permanent hearing loss. NIHL can result from a single loud noise - a firecracker or gunshot - or from noise over a gradual period of time.

How can you prevent noise-induced hearing loss?
1. Wear adequate hearing protection when exposed to loud noise at work or play. Disposable, foam ear plugs cost less than $2 per pair and can be purchased at mass retail chains like Target, hardware stores and sporting good stores.
2. Pay attention to the noises around you. Whenever possible, turn down the volume.
3. Alternate a noisy activity with a quiet one to give your ears a rest.
4. Spread the word about the dangers of noise.

Facts you should know:
More than 28 million Americans have a hearing loss. During a recent ten-year school district study, the incidence of hearing loss increased in eighth graders 400 percent.

Sensorineural damage
Damage to the hair cells and cochlea caused by genetics or overexposure to sound
is the largest single form of hearing loss, affecting 17 million Americans.

Excessive sound exposure damages hearing by over stimulating the tiny hair cells within the inner ear. There are between 15,000 and 20,000 of these microscopic sensory receptor sin the snail-shaped cochlea (pronounced COKE-lee-ah). When these hair cells are damaged, they no longer transmit sound to the brain.

The maximum exposure time for unprotected ears per day at 90 dB is 8 hours. For every 5 dB increase in volume, the maximum exposure time is cut in half.

95 dB = 4 hours
100 dB = 2 hours
110 dB = 30 minutes
120 dB = 7.5 minutes

Some common sources of loud sounds:

Lawn mower: 90 dB
Snowmobile: 100 dB
Car horn: 110 dB
Baby's cry: 115 dB
Rock concert: 115-120 dB
Farm implements: 90-110 dB
Firearms: 125-140 dB
stereo headphones: 105-110 dB

Noise-induced hearing loss affects both the quantity and the quality of sound. Understanding human speech becomes difficult because words become indistinct. People sound like they are mumbling.

Hearing damaged by noise is permanently lost and cannot be repaired. Hearing aids amplify sound for remaining hearing, but they do not fix hearing like eye glasses fix vision.

It doesn't matter whether you like the sounds you are exposed to. An orchestra playing Mozart at 120 dB will damage your hearing as quickly as Metallica playing at 120 dB.

Tinnitus, a sensation of ringing, hissing, buzzing or clicking in the ears affects at least 15 percent of the U.S. population.

Noise is the greatest threat to the ears and hearing of all Minnesotans, young and old alike.

In Minnesota, a highly agricultural state, one of the leading causes of noise-induced hearing loss is exposure to farm equipment and animal noises. Hearing Conservation of the Agricultural Community, a study conducted by James E. Lankford of Northern Illinois University, found that approximately 92 percent of males and 66 percent of females felt they had lost some of their hearing.

When tested for sound levels, the loudest noise sources on the farm were listed as:
1) tractors
2) grain dryers
3) combines
4) chain saws
5) grain feeding
6) grain blowers
7) animals

Fun Facts:

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