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Noise is an unavoidable part of all of our lives. In the shop all the tools we use make some noise. Right now I am sitting in an office that was designed to be soundproof, yet the hum of the shop can still be easily heard. Most of us have been told by our parents, probably when we were younger, to turn down our radios or televisions because we would go deaf if we didn’t. At the time, we probably didn’t believe it, but it turns out that Mom and Dad knew what they were talking about. Exposure to loud noise can, in fact, impair your hearing. My father was a carpenter for much of his life and he was hard of hearing from the time I can remember, likely from using tools without protecting his ears.

Some people consider noise a pollutant. You can’t smell it, taste it or touch it, but its power to cause harm is considerable. The Boston Globe calls noise “America’s most pervasive pollutant,” and The Daily Express of London refers to noise as “The worst pollutant of our time.” We have evidence that noise was a concern in ancient times as well. Julius Caesar reportedly banned wheeled traffic through the center of Rome during the day.

Studies have shown that too much noise can cause you to become ill. High blood pressure, disrupted breathing rates, poor sleep habits and ulcers are some of the problems people may experience when exposed to dangerous levels of noise. The most common problem created by too much noise is damage to your hearing. Obviously this can be a serious problem. If you have not evaluated the noise levels in your shop, it is important that you do so.

First, we have to determine how loud is too loud. Noise levels are measured in decibels (db). The higher the decibel level, the louder the noise is. Anything louder than 85 db is considered dangerous to your ears. When the ear is exposed to high decibel noise, the tiny hair-like cells in the liquid filled cochlea area of the ear are damaged. Unfortunately, this damage is always permanent. Frequent exposure to this type of noise is dangerous, and eight hours or more on a daily basis is considered prime conditions for hearing loss.

So how loud is your shop? I recently was able to borrow a sound meter to test the sound levels in our shop. While this was not a “scientific” test, it does give a general idea. Our shop has 25 workers using various tools. Most of the tools we tested can be found in both solid surface as well as stone shops. The left column shows the decibel levels of the various tools. For comparison, the right column shows the decibel levels of other noisemakers we are familiar with. All measurements were taken at a distance of 2 to 3 ft. from the tool, or the approximate distance between the tool and the ear during normal use.

Drill-95 db ------------------------------------------------- Motorcycle-95 db
Random orbit sander-105 db ------------------------- Boom box-100 db
Hand-held router-110 db ------------------------------- Car horn-110 db
Air gun-100 db -------------------------------------- Snowmobile-100 db
CNC-110 db ----------------------------------------- Rock concert-110 db
Air compressor-110 db -------------------------- Football game-112 db
Miter box-115 db ------------------------- Jet plane at the ramp-120 db
Panel saw-110 db ----------------------------------- Chain saw-115 db
Shop general noise level-85 db -------------------- Heavy traffic-85 db

I thought it was interesting that tools we might not consider dangerous to our hearing, like sanders and air guns, were above recommended safe decibel levels. Almost all tools tested at 100 decibels or above. Experts say that our pain threshold will tolerate 120 decibels of sound before being affected, but damage to the ear occurs at 85 decibels. Therefore, we can’t rely on physical discomfort to alert us to dangerous sound levels. We have to be aware of shop sound levels and take proper action to protect our workers.

Here are some recommendations:

1. Have the sound levels accurately tested in your shop. OSHA is a good place to start to see how you can have this done (www.osha.gov).
2. Have a class on hearing safety. There are experts in this field. Try your workers’ compensation provider. In many cases they can do the training or at least point you in the right direction.