Quick Facts on Hearing Protection in the Workplace
Exposure to loud noises has serious short-term and long-term health consequences for employees, including permanent hearing loss. Some effects of industrial noise, such as increased irritability and difficulty concentrating, reduce productivity and increase the opportunity for accidents. And while everyone recognizes the importance of hearing protection, “loud” may not be as loud as you think.
How Loud Is Loud?
OSHA’s definition of unsafe noise is complex, but it considers an average of 90 decibels (dB) over eight hours to be the upper limit of safe exposure. When industrial noise hits 85dB, companies must take action, which includes onsite monitoring, employee testing, and making hearing protection available. How loud is 85dB? Here are the dB levels of some common sounds:
Typical office noise: 50dB
Average traffic: 85dB
Power lawnmower: 90dB
Chain saw: 105dB
Heavy machinery: 120dB
Noise in the work environment can be measured in two different ways. Sound level meters are portable instruments that report the dB level in a particular location at a particular time. Firms use sound level meters to identify potential issues and make preliminary assessments. For a more accurate measurement, a noise dosimeter, a more sophisticated instrument, is worn by the worker to measure noise levels continuously throughout the shift. Dosimeters allow firms to make a more accurate determination of the level of noise workers are actually exposed to.
Hearing Protection Devices
The two most common types of hearing protection devices used in the workplace are ear muffs and ear plugs. Most ear muffs look like stereo headphones, and are available in a variety of styles; comfort and mobility are two important ergonomic factors to consider when making a selection.
Ear plugs also come in a number in a styles: moldable, non-moldable, with cord, washable and reusable being the most common options. Ear plugs can be custom molded to the wearer’s ear canal. While this option generally provides better noise protection and long term comfort, the cost is high and prohibitive for most industrial operations.
For many wearers, ear plugs offer greater comfort and mobility than ear muffs, and are generally safe. Ear plugs can, however, cause health problems such as pain if they are inserted to deeply, and earwax buildup after prolonged use.
In the U.S., all hearing protection devices are required to have an NRR (noise reduction rating). For example, in an environment of 85dB, a worker wearing a 30 NRR device will have an actual noise exposure of 55dB. By combining devices – using ear plugs with ear muffs, an additional 5dB to 10dB of protection over the higher NRR rated device will be achieved.
The Need to be Proactive
Hearing loss is a serious medical condition that seriously impacts one’s ability to lead a full and normal life. For employers, it is important to keep in mind that hearing loss is a function of noise level and the duration of exposure; often, symptoms do not become apparent until months or years of cumulative impact. By being proactive in managing noise exposure today, companies will reduce the occurrence of future hearing loss, productivity setbacks and insurance claims.