MRO Today - Ear relevant

Ear relevant
Hearing loss is prevalent, and preventable.
Wearing appropriate protection devices such
as earplugs and earmuffs is sound advice.

by Brian Myers

Noise is one of the most pervasive hazardous agents encountered in the workplace.

A 1996 National Institute for Occupational Safety and Health study indicated that as many as 30 million American workers are exposed to hazardous occupational noise levels on a regular basis.

The study also concluded an estimated 10 million Americans have impaired hearing at least partially attributable to noise.

Hearing loss is the No. 1 disability in the United States. Because hearing loss is gradual and permanent, most people don't realize their hearing is lost until it is gone forever.

Experts say continuous exposure to noise levels greater than 85 decibels (equivalent to the loudness of typical city traffic) can harm hearing.

A simple test will determine if noise levels are hazardous: if sounds are loud enough that you need to raise your voice to be heard at a distance of 3 feet or less, long-term exposure can be hazardous to hearing.

Noise-induced hearing loss is irreversible. However, it is 100 percent preventable. An important preventative measure is wearing the appropriate hearing protection.

Active vs. passive devices
Hearing protectors have come a long way from the leather earmuffs, cotton balls and shell casings used during and after World War II.

The passing of the Occupational Health and Safety Act and the introduction of the first foam earplugs in the 1970s revolutionized hearing protectors and hearing conservation programs.

Today, safety product manufacturers offer a wide range of earplugs and earmuffs.

A common trend is to add style elements to hearing protectors, such as interesting shapes, color combinations and packaging. To the hearing conservation purist, this innovation may seem frivolous, but style can play a vital role in motivating workers to carry and wear hearing protectors. Having the proper engineering to work effectively for the application is key; but style, coupled with effective training, can help drive compliance.

Another current issue being addressed by hearing protection manufacturers is correcting "overprotection." Hearing protectors that overprotect remove not only the harmful noise, but also verbal communications or other sounds that may be vital to job performance and safety. Protectors that solve this problem are now available in passive (no electronics) and active (with electronics) devices.

Active devices are more widely available in earmuffs, and a few options are available in custom-molded earplug styles.

If employees already carry a radio, active devices are a good communications option. Active devices typically cost at least $100.

A more cost-effective option in communications may be passive, flat attenuation or low-distortion protectors. These are available in both earmuff and earplug styles.

Most protectors reduce noise, but also distort it by cutting out more of the high-frequency sounds. Passive flat attenuation devices minimize this distortion while still reducing noise levels. Lower distortion improves communications. These devices may be worthwhile for individuals already having some noise-induced hearing loss, when conventional protectors may only further isolate them from other workers. They also are helpful when emergency instructions must be clearly understood or for machine operators who are concerned that wearing protectors will distort the sounds of their machines.

The best advice for selecting a communications solution is to give these devices a test run in the environment where they will be used. Most distributors and manufacturers are happy to arrange a product trial.

Continually evolving
Several innovations also have taken place recently within specific hearing protector categories. In the area of slow recovery foam protectors, a recent innovation eliminates the need for users to roll down the foam plugs. Generically called pod plugs, a user-friendly inserting stem replaces the foam, allowing for easy push-in insertion.

Semi-inserts, or "banded" hearing protectors, have seen some of the greatest innovation. These devices have been greatly impacted by style and options in the plug or tip design. These tips now include foam and are pre-molded; some are even metal detectable.

Innovative concepts for storage include adding a cord for carrying the product around the neck. One band style now includes a hinge, which allows the device to be worn in multiple band positions.

In the regulatory area, a trend worth noting involves the performance testing used to establish the Noise Reduction Rating (NRR).

Although independent testing of hearing protectors is not required to establish the NRR, many manufacturers have begun using National Voluntary Lab Accreditation Program (NVLAP) laboratories to test their product's NRR. The NVLAP program is administered within the Federal Department of Commerce and consists of adherence to well-defined protocols, record keeping and annual lab audits. Although this does not accredit specific test results, it gives assurance to lab methods and test equipment.

Company compliance officers, safety officials and department managers need to take every opportunity to improve hearing conservation programs and ensure the hearing health of employees. Hearing protection manufacturers are pushing to provide companies with all the safety, comfort and security that technology delivers.

Brian Myers is the product line director managing the E-A-R and Peltor brands of passive hearing protectors for the Aearo Company. He serves on the board of directors of the National Hearing Conservation Association.

This article appeared in the August/September 2000 issue of MRO Today magazine. Copyright, 2000.