Work Related Hearing Loss

Millions of people are exposed to dangerous levels of noise in the workplace every year. Hearing loss from noise exposure on the job has been a significant occupational health concern in most first world countries for more than twenty years. Every year, thousands of individuals experience preventable hearing loss due to high workplace noise levels.

High noise levels are known to cause hearing loss that can be permanent, which often cannot be corrected by a hearing aid or surgery. And even when briefly exposed to it, high noise levels can result in a short-term degradation in hearing, as if your ears were stuffed with cotton, or indicated by the sound of ringing in your ears, a condition called tinnitus. Such conditions can be short-lived or persist for hours after exposure. Importantly, persistent tinnitus or other loss of hearing can result from recurring exposure to high sound levels.

Also other forms of stress, including psychological, physical, as well as reduced productivity, can result from exposure to loud noise. It can result in accidents in the workplace because of interference with normal communication, reduced ability to concentrate, and overall diminished effectiveness of audible warning systems. Hearing loss from exposure to loud noise reduces one’s ability to hear sounds at higher frequencies, impairs normal ability to understand speech, and reduces one’s ability to interact and communicate normally with others. These impairments can have a profound effect on an individual’s life, from personal relationships with family and friends, to professional interactions that are essential and meaningful to both the affected person and those around them. Ultimately, it can lead to social isolation that can have psychological effects.

Your Hearing Machine: Outer, Middle and Inner Ear
When you hear a sound, your ear drums are struck by the vibrations of sound waves that have entered the outer ear, which are then transmitted on to the next parts in the chain: the middle and inner ear.  Your middle ear has three important small bones called the malleus, incus, and the stapes, Latin words for hammer, anvil and stirrup. These three bones transmit – and amplify - the vibrations from your ear drum on to the inner ear. In the inner ear, a tiny spiral structure called the cochlea converts those vibrations into nerve impulses. The cochlea is a fluid-filled vessel lined with microscopic hair cells. These tiny hairs respond and move to the vibrations in their fluid environment, sending nerve impulses along to the brain, resulting in our perception of sound. These hair cells are susceptible to damage from loud noise exposure, and hearing loss can occur.

Warning Signs In The Workplace

  • Take inventory of your hearing when you leave work, and notice if there’s any humming, ringing or other loss of hearing.
  • When you’re on the job, do you have to shout to be heard, even if co-workers are as close as arm’s length?

 Measuring Sound Levels
Alexander Graham Bell invented a unit called a Bel to measure the level of sound. Engineers later invented the decibel (deci-Bel), which is 1/10 of a Bel, because the Bel was too large a unit. In order to match the perception we have of loudness, Graham Bell used A-weighted sound levels, and when used with term decibel, resulted in the common shorthand dBA. The measurement of dBA happens on a logarithmic scale, meaning that a few decibels of change means a large change in noise level.  So a few dBA of increased levels can mean a more significant danger of hearing damage.

Reducing the Hazards In The Workplace
Controlling noise is the most important strategy, which can reduce or eliminate hazardous exposure. By lowering sound levels a few decibels, hearing hazards can be mitigated, with the immediate effect of improving the workplace.

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