Chair's Message - Spring 2011
By Lee D. Hager
So What's New?
Actually, plenty - and thanks for asking! I'm taking the opportunity of this Chair's Message to give you all a little insight as some new (and newish) developments in the world of hearing conservation. Many thanks and kudos to Dr. Theresa Schulz, CAOHC Council representative for the American Academy of Audiology (AAA). It was Theresa's article in Professional Safety, the journal of the American Society of Safety Engineers (ASSE - also a constituent of the Council) that brought this idea to mind.
New Technologies
There has been a big increase over the past few years in technologies intended to help in our efforts to protect hearing. One of the largest areas of development in this area is individual fit testing for hearing protectors. Several companies have developed different approaches to help determine whether an individual user is getting enough protection from their earplugs (and yes, most of the systems will test earplugs but not earmuffs) to be safe in the noise they work in each day. At the recent National Hearing Conservation Association (NHCA) conference, Bill Murphy of NIOSH organized a day-long session where several of these systems were described and demonstrated. This appears to be a growing - perhaps a looming - advance in hearing conservation practice. For those of you with access to this publication, check out the article in the March issue of Noise & Health for a summary.
In addition, reductions in both size and cost have made electronics a viable supplement for some types of hearing protectors. Some allow outside noise in, controlled to a safe level (thus eliminating the "I can't hear my machine" excuse for not wearing hearing protection); some interface with different types of communication setups like 2-way radios or intercoms. Some integrate noise measurement instrumentation with the hearing protector, effectively providing a "protected exposure" that indicates the true noise dose getting to the workers' ear instead of the noise level measured outside. As the electronics get better, cheaper, and smaller, look for more and more of this kind of integration and more new developments in electronic aids for hearing conservation.
Hearing Testing Technologies
Another area of focus at the NHCA conference was the application of otoacoustic emissions (OAE) in hearing conservation settings. OAEs are very faint sounds that are actually generated by your hearing system - so faint that it's unlikely you can hear them, but detectable with specialized equipment. Most of the systems work by playing a sound into the ear, then "listening" for the OAE as a sort of echo. Measuring the sound coming out of the ear can give an indication of the health of the ear, and may be a more sensitive measure of early hearing loss than the audiograms we give today. Check out the 2011 NHCA Conference Proceedings for more information.
Pending Regulatory Changes
The EPA has been planning to change the way hearing protectors are labeled for several years - while it may not seem like it to you and me, this is actually a blink of the eye in Washington terms. Work continues on the new label and evaluation approach. While nothing is final until it is final, expect the new label to reflect a range of protection instead of a single number Noise Reduction Rating (NRR). The approach described by the EPA so far also will permit the evaluation of electronic hearing protectors (like the active cancellation devices that knock down low frequency sound using "anti-noise") as well as devices designed to change the amount of noise they block based on how loud the noise gets - "non-linear" hearing protectors, like some of those designed for shooters and weapons fire.
OSHA pursued a bit of a false start in the noise arena by publishing a notice that they planned to change the way noise rules would be enforced. Based on interpretations of the law from the early 1980's, OSHA has not emphasized noise control - the reduction of workplace noise - unless very specific circumstances were met. While there has always been a requirement to implement feasible engineering controls for noise, a matrix was developed that very tightly defined "feasible" such that most employers found it easier and less expensive to provide hearing conservation programs instead of noise control. Last fall, OSHA indicated that they intended to change the compliance definition of "feasible" to - well, feasible. As Webster would put it, feasible meant "capable of being done". This raised the specter of a new compliance emphasis on controls, and raised the ire of many industrial employers. OSHA has since backed away from their proposal, but plans to continue to look at ways to reduce hearing loss in American workers.
But Some Things Never Change
Hearing loss continues to accrue. According to the Bureau of Labor Statistics, 21,700 new cases of work related permanent, irreversible hearing loss were recorded in 2009 - on top of the 22,000 the year before and the 23,000 the year before. Since OSHA started keeping track of hearing loss separately on their Form 300 in 2004 workers have suffered over 143,000 cases ofunnecessary, preventable hearing loss. We understand noise and we understand testing hearing; maybe we all need to do a better job of understanding how to prevent hearing loss in the first place.
References
Schulz, TY. Key Hearing Conservation Issues for 2011 and Beyond. Professional Safety, April 2011. cited 4.15.11 from
http://www.asse.org/professionalsafety/best-practices.php
Davis, R. (editor) Noise and Health. Volume 13, Issue 51, pages 85-200. cited 4.15.11 from http://www.noiseandhealth.org/currentissue.asp?sabs=n
National Hearing Conservation Association. 2011 Conference Proceedings, available for purchase from NHCA, nhcaoffice@hearingconservation.org