Protecting employees on and off the job is critical for today’s workforce.
By Gary Ganson, CIH, CSP
Several professionals in various industries have made efforts to protect workers against hearing loss. And yet, agencies collecting data on occupational hearing protection are seeing a continuing rise in the number of people sustaining hearing loss—and at a much younger age.
The Bureau of Labor Statistics reported since 2004, nearly 125,000 workers have suffered significant, permanent hearing loss.
What are the contributing causes? The research points to a new generation growing up with technologies introducing more noise directly into the ear. The culprits range from car audio systems, iPads, iPods, and laptop computers connected to earbuds to high-powered yard equipment such as lawn mowers, chain saws, weed trimmers, leaf blowers, snow blowers, and chippers.
The problem isn’t just amplitude (how loud), but also frequency (how often). The Hearing Loss Association of America reports one in five adolescents has a noise-induced hearing loss.
When the Walkman portable audio cassette player was introduced by Sony in the mid-1980s, I was working with a plant manager who decided to start letting employees who were doing repetitive line work use the device with earbuds to help alleviate the tedium of the factory line.
The ambient conditions of the workspace were already close to 90 decibels and hearing protection was required. So when the workers put their earphones on to listen to their Walkmans, they had to turn the volume up just to hear the music. To compound the problem, the external ear collects sound, transfers it to the ear canal, and amplifies it naturally.
The plant manager thought he was doing the right thing and improving the working conditions for the employees when instead he was actually allowing them to be exposed to a hearing hazard. The noise level was measured by a sound level meter at 105 decibels. The OSHA permissible exposure level for noise is 90 decibels.
Identifying the Hazard
Working around drill rigs requires an effective hearing protection program. That begins with identifying the type of noise and frequency, which can be measured relatively easily with a sound level meter, and then providing a hearing protection device matching the noise being produced.
Sound measurement meters can be rented to conduct the noise measurement or consultants can be retained to measure and evaluate worker exposures to noise.
Drill rig noise is usually consistent depending on the “rpm” of the drill and the different rock formations the bit is drilling into. Measuring the frequencies of drill rig noise and amplitude or how loud it is helps employers select the hearing protection device that will give employees the protection they need.
Despite what a hearing protection salesperson might try to say, no “one size fits all” when it comes to hearing protection. Having good measurement information is critical in making your selection!
Once the noise levels have been measured, selecting the hearing protection device is determined by comparing the noise reduction rating (NRR) provided by the manufacturer to the measured levels. The NRR is a number generated by the manufacturer of the device and indicates the reduction in sound level provided by wearing the device, whether it’s earplugs or earmuffs.
OSHA Standard 29 CFR 1910.95 related to hearing protection provides calculations employers can use to figure out the effective noise reduction required—simply by plugging in the manufacturers’ NRR. The OSHA calculation will make the effective number even lower than the NRR. Any noise above 90 decibels requires engineering controls and hearing protection based on eight-hour weighted averages.
Noise measurement and hearing protection is something OSHA looks at critically because both the technology to measure and the technology to protect are so readily available.
OSHA standard aside, it just makes common sense to have an effective hearing protection program in place because hearing loss damage is irreversible and compensation can be costly. Also, the more educated our workforce becomes about noise and hearing loss, the better they protect themselves while away from work.
Improved Protection Technology
Hearing protection technology has changed and the material and technology available to make hearing protection devices have gotten better—softer but denser and easier to apply.
Earplugs and earmuffs are examples of passive hearing devices, but today active hearing protection technology is also available. These devices don’t shut out the noise, but cancel it. They measure the ambient sound and frequency and generate an out-of-phase signal in the exact same frequency, which in effect cancels the noise before it reaches the ear.
These devices, used both for canceling out noise exposure as well as canceling out background noise, come in lots of different forms, but are more expensive. With any hearing protection device—earplugs, earmuffs, noise cancellation—training in proper use and selection is critical to success and safety.
OSHA has a one-sentence definition of training:
The employer shall ensure that each employee is informed of the following: the effects of noise on hearing; the purpose of hearing protectors; the advantages, disadvantages, and attenuation of various types and instructions on selection, fitting, use, and care; and the purpose of audiometric testing and an explanation of the test procedures.
In addition, the results of hearing tests must be discussed with workers. That is all that’s required from OSHA. To be more diligent, I recommend employers take hearing protection training to the next level and include noise exposure off the job. Training should include explaining the combined effects of noise and what it does over a long period of time.
Many employers even provide hearing protection devices to their employees to take home and use when they’re mowing the lawn, using a leaf blower or chain saw, or out somewhere shooting a gun.
So what does an employer do if a worker suffers hearing loss despite an excellent hearing protection program? For example, what if an employer’s program is taking time-weighted measurements, conducting audiometric testing, providing hearing protection devices, and training workers to effectively use the protection.
Some employers are attempting to deny workers’ comp claims when they know they have an effective hearing conservation program in place and are doing everything they should.
Training for Home Noise
Employers might have no control over what workers do in their off time, but they can still address these important issues. I think employers are not doing a good job of training and counseling if they don’t make it clear to employees what they do off the job when it comes to noise exposure can be just as detrimental as what they do on the job.
Take the intense sound level of chain saws, weed trimmers, and mowers. They all exceed 90 decibels and sometimes 100 decibels. Generally, anything motorized by gas or power will produce a higher noise level than the work area. This is an important discussion to include in training since hearing loss can start as low as 80 to 85 decibels if we are continuously exposed to those levels.
When evaluating noise levels and exposure times for damage to start occurring, you have to consider sound energy.
OSHA uses the 5-decibel doubling rule. Under the OSHA standard, a worker can be exposed to 90 decibels or less for eight hours—but increase the noise level to 95 decibels, and the same exposure or potential damage would happen in half the time or four hours! At 100 decibels, hearing damage can happen within two hours! In other words, operating a chain saw at home in the evening and producing 100 decibels of noise for two hours will potentially cause the same damage to our hearing ability as being exposed to 90 decibels for a regular eight-hour shift at work.
Information like this is what many of us have not effectively communicated to our employees in the past. They have a responsibility to follow hearing safety procedures and policies on the job, but they must also understand all the different sources of sound they are exposed to and realize off-the-job exposures can be no less damaging.
The bottom line? Employers have a duty under OSHA to protect their workers, but employees also have a duty to take that information and apply it to their own well-being. Employers need to start holding employees more accountable for protecting themselves and workers need to feel pride of ownership over their own senses. The hearing protection technology is so readily available there are no good excuses anymore.
Employers need to hold conversations about hearing safety off the job with their workers. It doesn’t add much time to a training program and it lets people be masters of their own destiny.
And making protection devices available to workers to take home has a minimal cost, but a priceless value. Hopefully it will result in valuable employees who are with you for a long time.
Do you hear that?