Hearing aids have a long history of technological innovation. If you look only at the achievements of the past 10 years—at least since the widespread acceptance and utilization of multichannel wide dynamic range compression, directional microphones, and the digital age—it’s easy to see how important and fast-paced the R&D of hearing aid manufacturing has become. Today, hearing aid product life cycles are on the order of 9-18 months. Because of this, we have a tendency to become transfixed on amplification and its benefits for hearing aid users—particularly for those people with moderate to severe hearing losses (generally, older users). Not surprisingly, this demographic constitutes the majority of today’s hearing aid user population, but does not represent the largest number of people who could benefit from amplification (those younger than age 65).

Due to our focus on hearing aids and hearing care for older users, we often lose sight of the importance of hearing loss prevention and preserving the residual hearing of those who are at risk for hearing loss—particularly younger people in the workforce. Although lots of press coverage has been devoted to the potential hearing damage associated with high volume levels in iPods and other MP3 personal listening devices, very little is ever said about the dangerous sound levels encountered in the workplace—where people are exposed to dangerous noise on a daily basis. Here, one instinctively thinks of large factories and manufacturing plants, but there are many more workplace settings that expose workers to dangerous noise levels. These include, but are certainly not limited to, engine repair shops and recreational vehicle dealerships, carpentry and construction sites, farming and logging operations, and law enforcement, rescue, and military facilities.

Additionally, the implements we regularly encounter at home—including lawnmowers, snowblowers, and electric hand tools—can be incredibly loud and are sometimes used for long durations. At my home, we have a vacuum cleaner that emits such a loud noise that it even terrifies our cat—an animal so lethargic and sedentary I once seriously considered renaming him Bill Wyman (after the legendary, and very stationary, Rolling Stones bass player). I own a belt sander that is so loud that my elderly neighbor emerged from her house last summer to check the sky because she mistook the sander’s din for a tornado siren. Many of us also indulge in pastimes that can place our hearing at risk: driving recreational vehicles, attending racing events and rock concerts, hunting and target shooting. These are “educational opportunities” custom-made for hearing care professionals. In fact, the profession and the industry has a moral obligation to inform people about these potential hazards.

This special edition of The Hearing Review, which was assembled and co-edited by Marshall Chasin, AuD, and Lee Hager, presents a wonderful primer on hearing protection devices (HPDs) and occupational noise-induced hearing loss (ONIHL). How do earplugs and earmuffs modify sound? What should you take into consideration when assessing the noise reduction rating (NRR) of an HPD? Who should wear earmuffs, earplugs, or both? What is the best way to protect against high-impulse noises like firearms? What can be expected for future HPDs and their noise-reduction specifications? These are questions answered in this edition. The Hearing Review would like to thank Chasin and Hager, as well as all of the authors, for their contribution to this excellent survey on HPDs and ONIHL.

Check out HR’s new online calendar. A Calendar section is a new feature in HR’s rapidly evolving Web site to see the events and educational opportunities available for hearing care professionals. Also, make sure to sign up for our weekly e-newsletter, HR Insider.

Karl Strom
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