Say What?

April 1, 2001

Say What?

Excessive noise affects more than your hearing

By Michelle Garetson

April 2001

Can you hear what your body is telling you? Long-term exposure to high noise levels in our work environment affect much more than our hearing. Continuous noise, such as the whine of a drill or the reverberations of aircraft engines over the work shift can also jangle nerves and disrupt digestion. Many aircraft technicians, already fighting their circadian rhythms through shift-work, are further aggravating sleep patterns through prolonged exposure to noise. So, what can be done? Developing an understanding of what your environment is telling you can help you and your employer better address noise problem areas.

How loud is too loud?
Noise is one of the leading causes of hearing loss in the 28 million people with impaired hearing in the United States. The sad part is that noise-induced hearing loss, though preventable, is permanent. The criteria for a sound to be loud enough to cause damage involve both the level of intensity and the length of exposure to the sound. Sound intensity is measured in decibels (dBA). Standards set by OSHA (Occupational Safety and Health Administration) indicate that continued exposure to noise over 85 dBA will eventually harm hearing. According to OSHA, the exposure time allowed is cut in half for every 5 decibel increase. Some benchmark decibel levels to track are as follows: pneumatic drills and jet plane at the ramp both weigh in at 120 dBA; airplane at takeoff, 140 dBA; and jet engine at takeoff, 150 dBA. Noise levels over 140 dBA can cause hearing damage after a single exposure.

"Temporary" threshold shift
This is a misnomer. Noise-induced hearing loss is cumulative and tends to occur gradually and painlessly. After exposure to loud noise, a person may experience ringing in the ears or have difficulty hearing. This is known as "temporary threshold shift." After a few hours (or possibly, a few days), this temporary shift in hearing returns to normal. Yet, through repeated exposure, this temporary shift in hearing can become permanent.

Tension meter
Studies have found noise to be associated with increased aggression. Exposure to noise also has been linked to elevations in blood pressure as loud noises raise adrenaline levels. We’ve all been stressed at one time or another over noises from a dripping faucet or a neighbor trying, unsuccessfully, to troubleshoot his lawnmower’s engine problems for hours on end. Even though these noise assaults are not necessarily ringing in at hazardous levels, they will still irritate us until we can subdue or eliminate them — the noises, not the neighbor!
Prolonged tension in the body makes it difficult for meal enjoyment as well as proper digestion. It stands to reason then that if anxiety levels are high and remain high, reaching for the antacid and other hypertension relievers, or possibly alcohol or cigarettes; will increase in frequency as noise sufferers try to diffuse stress.

Sleepless in Seattle
Although we all know someone who could probably fall asleep next to an operating jet engine, those persons are the exception, not the rule. Noise is one of the most common forms of sleep disturbance and when sleep disruption becomes chronic, adverse health effects can result. Beyond that, those suffering from lack of proper sleep can pose a safety risk through reduced concentration, which could lead to workplace injuries or worse.

Protect your hearing
Occupational noise-induced hearing loss is preventable so no legitimate reason exists for any worker to incur an occupational hearing loss. An effective Hearing Loss Prevention Program (HLPP) should be integrated into the company’s overall health and safety program and requires full commitment from management and workers. The result will be fewer workers’ compensation claims and safer shops.

April 25, 2001 is International Noise Awareness Day. From 2:15 – 2:16 p.m., regardless of location, please take this minute to find quiet.

Additional resources...

National Hearing Conservation Association
National Institute for Occupational Safety and Health
Occupational Safety and Health Administration