By Donald Melanson posted Mar 15th 2011 12:22PM

We’ve already seen the principle of bone conduction be applied to headphones, but Sonitus Medical is taking the idea to a whole new level with its SoundBite dental hearing aid, which has just received the necessary European CE Mark certification (it already has FDA approval). As you can probably surmise, the device is a hearing aid that’s placed on your teeth, although it’s not actually implanted or attached in any way — it’s simply custom fitted to the person’s upper back teeth. The other part of the package is a more standard-type hearing aid unit that’s worn behind the ear, which processes and wirelessly transmits to the device in your mouth. That’s obviously not intended for cases when a simple hearing aid will do, but Sonitus says the system can help people who are “essentially deaf” in one ear regain their spatial hearing ability.

New technologies make the goal of OSHA’s Hearing Conservation Amendment, the elimination of noise-induced hearing loss, very feasible.

By Brad Witt, MA, CCC-A  March 1, 2011

OH&S Magazine, Vol. 80 No. 3 

When OSHA enacted its new Hearing Conservation Amendment in 1983, evidence at the time suggested it would be a strong force in eliminating noise-induced hearing loss (NIHL) from the workplace. But nearly 30 years later, reality has shown the high hopes to be unfounded. Occupational hearing loss continues to be called “the most common permanent and preventable occupational injury.”¹ And the Bureau of Labor Statistics reports that, despite decades of legislation and intervention by employers, the average number of cases of recordable NIHL in industry has been about 25,000 per year for the past five years.²

The noise hazard remains the same in 2011, but now the landscape for hearing conservation is much different. Technology has fundamentally changed the way we measure the effectiveness of hearing protectors, and several long-awaited changes in regulations appear to be making headway toward enactment. Here is an update of issues and changes that have a major effect on hearing conservation efforts for your noise-exposed workers.

OSHA Rulemaking
At the core of OSHA’s Hearing Conservation Amendment are two numbers: the 90 dB Permissible Exposure Limit (PEL) and the 5 dB Exchange Rate (ER). The PEL is OSHA’s definition of maximum safe noise; any 8-hour exposure exceeding this level requires hearing protection for noise-exposed workers. The Exchange Rate describes the rate at which allowable exposure time is halved; a “5 dB exchange rate” means allowable exposure time is halved for every 5 dB increase in noise levels.

These numbers have their roots in the Walsh-Healey noise regulation of 1969. But the preponderance of scientific evidence since then suggests these levels are far too lax in their protective value. The 90 dB PEL and 5 dB ER still allow a substantial percentage of noise-exposed workers (23 to 32 percent, by NIOSH estimates) to suffer NIHL. This makes workers in the United States far less protected than their counterparts in Europe, Australia, or most other parts of the world.

Reducing the PEL by just 5 decibels (from 90 to 85 dB) would put OSHA in good company. Nearly every country in the world except the United States uses the more-protective 85 dB limit value, and even NIOSH and the U.S. Department of Defense define the 85 dB PEL and 3 dB ER as best practice. Professional organizations including the National Hearing Conservation Association and American Industrial Hygiene Association called upon OSHA last year to reduce the PEL from 90 to 85 dB and adjust the ER from 5 to 3 dB. Most noise dosimeters now allow users to select either 3 or 5 dB exchange rates.

While OSHA has resisted efforts to reopen or update its Hearing Conservation Amendment since its enactment in 1983, there is a growing expectation for a change to be made soon. This is due in part to the fact OSHA may be obligated to update its hearing conservation standard to accommodate a change in the way hearing protectors are rated by the Environmental Protection Agency.

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Workers no longer have to be subjected to noise’s damaging effects — or suffer frostbite, for that matter.

By Yoel Naor, March 1, 2011

OH&S Magazine, Vol. 80 No. 3 March 2011

The wearing effects of noise pollution are well documented: Workers are put at risk for elevated blood pressure, hearing loss, and stress-related disorders. Even heart attacks have been attributed to chronic exposure to excessive noise. Researchers at Yale University concluded that stress caused by negative noise exposure can increase vulnerability to neuropsychiatric disorders.

While many of the problems from noise exposure are cumulative, short-term effects, such as the inability to concentrate and communicate, significantly affect productivity. The easiest rule of thumb is that noise is excessive when people can’t speak in normal conversational tones within a distance of 6 feet, or 2 meters. In an emergency, this inability to communicate can be life threatening.

Some IT workers are exposed to chronic noise pollution because of the fan speeds needed to cool equipment. They also are subjected to working in environments that are hyper-cooled. IT hardware generates a great deal of heat, and thermostats must be set low enough to offset this to prevent equipment burnout.

A recent IDC analyst study found the number one challenge facing data centers is power and cooling. According to a study by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, during a four-year period, the maximum temperature for operating IT equipment went up by 9 degrees Fahrenheit (5 degrees Celsius). A lapse in an IT department’s cooling system of only a few minutes can result in server meltdown, a very expensive proposition from both the equipment and lost time and data perspectives.

The resulting cost of overcooling and creating noisy IT environments is high, both in terms of human cost and budgetary outlay. Poor work performance, absenteeism, chronic health problems, and soaring electrical bills are obvious outcomes of IT equipment stored in traditional dedicated storage rooms.

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The following is an excerpt of an inquiry from a Workplace INTEGRA client to our Director of Audiology, George Cook, Au. D., CCC-A.  Edits were made to conceal the client’s identity and employee name.

Dr. Cook,

I have a situation in the XXXX location of our company and need your professional opinion.

Attached is an employee’s hearing record. This employee states that he cannot wear hearing protection on the job due to the fact he feels unsafe. He states he cannot hear other employees speaking to him while wearing hearing protection.

My questions are:

•  After reviewing this employees hearing record, can you please tell me if it is possible that he cannot hear other employees while wearing hearing protection, earplugs, or muffs?
• If the answer is yes to question number one, can you please suggest if there is a hearing protector that can help the employee hear other employees?

Thanks,

I have reviewed (employee) hearing tests.  I would believe wearing hearing protection may interfere with his understanding other employees at times.  He has a mild hearing loss in the speech range in the right ear and low normal hearing in the speech range of his left ear.  Additional attenuation from hearing protection would cause additional hearing difficulty.  However, this type hearing loss can sometimes be fitted with musician hearing protectors.  The difference between standard hearing protectors and musician’s protectors is the amount of attenuation in the high frequencies.  Standard hearing protectors will attenuate more in the high frequencies than in the lower frequencies.  Musician’s protectors provide a relatively flat (+/-5dB) attenuation across frequencies.  The purpose of these protectors is to attenuate sound without distorting the signal or music.  Flat attenuating hearing protectors have been successful in fitting employees with an already existing mild loss in the speech range.  There are several manufactures of musician’s hearing protectors. One of the more common names is Etymotics, with models ER9m ER15, and ER25, with increasing levels of attenuation.  Westone provides a custom molded musician’s protector and EAR has a light insert musician’s protector.  You might search the Internet for ‘musician’s hearing protectors’ and come up with a few more providers.

In addition, there are manufacturers of amplified hearing muffs.  These muffs will amplify up to 82dB SPL and protect with levels above that.  EAR/Peltor manufactures a gunfire muff, Tactical VI or Tactical VII, which will limit background noise to 82dBA.  This muff has been recommended successfully for employees with mild speech frequency loss working in intermittent noise levels needing to hear speech. The muffs cost between $140 and $170 so I would try the insert plugs first.  Once you introduce a new protector, everyone wants it.  They can be difficult to wear as they will amplify background noise in quiet as well as speech.  But if nothing else works, they deserve a try.  Both Bilsom and Peltor manufacture amplified muffs.  Sperian also manufactures an amplified muff, the Impact and Impact Sport models.

The Cadillac muff of this type is the Sensear.  They are designed to allow speech communication in the presence of background noise.  They are in the $400 range.  I tried on a pair recently at the NHCA Conference in Phoenix, AZ and they work well.  

As a precautionary note, this employee’s hearing has shown significant change in the right ear over the past few years.  The low frequency change is not characteristic of noise exposure.  He should be referred to an ear specialist for diagnosis and possible treatment.

His medical health history and medications need to be reviewed by his physician.  This employee must not work in noise without protection.  He has demonstrated hearing change and must protect his hearing from any contribution from noise on or off the job.

Regards,

George Cook, Au. D., CCC-A

 The supplemental issue of the International Journal of Audiology highlights research that was presented at NHCA’s 35th Annual Conference last year.

• Feb 05, 2011

NIOSH and the National Hearing Conservation Association have teamed to produce a supplemental issue of the International Journal of Audiology that highlights research that was presented last year at NHCA’s 35th Annual Conference. The studies featured in the issue focus on expanding the traditional boundaries of hearing loss prevention and sharing knowledge internationally.

“Noise-induced hearing loss is a preventable issue affecting workers across the globe,” said NIOSH Director Dr. John Howard. “This collaboration of the leading voices in this area is an important part of furthering our knowledge and research in how to better protect all workers.”

The research topics include:

• Noise-induced hearing loss in different economic sectors in Asia
• A large-scale epidemiological view of audiometric thresholds of adolescents and adults free from occupational noise exposure
• A new perspective on “normal hearing” in college students
• An exploration of the real-world challenge of promoting use of hearing protectors by construction workers
• Examining the challenges of minimizing hazardous sounds while preserving audibility and situational awareness
• How innovation, interdisciplinary collaboration, and education can potentially contribute to a successful hearing loss prevention program for musicians

Additional support was provided by Safe-in-Sound Excellence in Hearing Loss Prevention Awards™, the Council for Accreditation in Occupational Hearing Conservation, Etymotic Research Inc., G.R.A.S Sound & Vibrationm and HCI National Mobile Health Programs.

The 2011 Safe-in-Sound Excellence in Hearing Loss Prevention Awards™ will be presented at the 36th NHCA Annual Conference in Mesa, Ariz., on Feb. 25. Nominations for the next round of awards will be accepted until Sept. 1, 2011. For information about the awards and this year’s conference, visit this website.