Anyone who has spent time in a woodworking shop probably understands the extent to which woodworkers are susceptible to noise-induced hearing loss. Although hard numbers are difficult to come by for the woodworking industry as a whole, according to the National Institute for Occupational Safety and Health (NIST), approximately 30 million workers in the US are exposed to hazardous noise on the job, and individuals aged 45 to 64 experienced a 26 percent increase in hearing problems between 1971 and 1990. Among trade workers, 44 percent of carpenters and 48 percent of plumbers report they have a hearing loss, and 49 percent of miners are likewise impaired by age 50.

Both the intensity of the hazardous noise and the duration of the exposure to it contribute to hearing loss. Experts agree that an 85 decibel (dB) average noise level over an eight-hour workday is harmful to hearing. But a worker may not notice that decline in hearing immediately, as it can possibly take several months or years to become noticeable.

Brad Witt, Audiology and Regulatory Affairs manager for the Bacou-Dalloz Hearing Safety Group, has been an industrial audiologist for 22 years, and is also the former president of the National Hearing Conservation Association. For 14 years he managed a company that provided hearing conservation services at 175 locations in the western U.S. His work with the Bacou-Dalloz Hearing Safety Group allows him to participate in the preventive side of occupational audiology and educate workers about noise-induced hearing loss before it occurs. The group is a combination of Howard Leight Industries, a manufacturer of earplugs for both industrial and retail markets, and Bilsom, a developer of sound management and earmuff technologies.

Recently, Wood & Wood Products talked with Witt about hearing loss, and what steps a company or individual can take to prevent and protect against it.

Wood & Wood Products: How long have you been dealing with woodworking companies?

Witt: In a sense, I've seen both sides of the noise problem in the industry. My father operated a carpentry shop in support of his general contracting business, and I was hired as a boy to clean up around the shop. I remember thinking, "Gee, that shaper is pretty loud." Thirty years later, I was contracted by several woodworking shops to take noise levels and provide audiometric testing to the noise-exposed workers, and I still thought, "Gee, that shaper is pretty loud." My father
actually suffered some hearing loss.

W&WP: Do woodworking companies have special characteristics to address in regards to hearing protection and hearing loss?

Witt: There are two factors that make noise particularly hazardous in the woodworking industry. The first is the worker's proximity to the noise source. In woodworking, the high noise source is often just an arm’s length away from the operator’s ear, not across the room or down the hall. Secondly, the intermittent nature of the noise makes it deceptively hazardous. Workers might feel they don't need protection since they are only going to be on the machine for "just a minute." But those one minute noise exposures, multiplied many times throughout the day, are enough to take away the hearing.

W&WP: What, if any, are physical symptoms of hearing loss?

Witt: That is precisely one of the traps of noise-induced hearing loss: the noise-exposed worker does not really feel any pain, there is no bleeding, no bruising, no visible scars, and no outward signs of damage. When loud noise damages
hearing, it affects the nerve cells deep inside the cochlea of the inner ear. And once those nerve cells are gone, they are gone for good. It causes a permanent loss of hearing. There is no pill, no surgery, no treatment to restore hearing lost to noise exposure.

W&WP: What are the long-term effects of exposure to hazardous noise?

Witt: First is the obvious loss of hearing. But it is not the volume of the incoming sound that is affected — it is the clarity of that sound. Workers with noise-induced hearing loss typically complain, "I can hear the speaker, but I just can't understand what's being said." Noise damages our ability to hear the high-frequency sounds of speech — sounds like s, t, ch, k, f, th, sh and p. If you take away those sounds, incoming speech often sounds garbled. The second long-term effect of noise damage is tinnitus, or ringing in the ears. Occasional ringing is quite normal in most people, but workers with noise-induced hearing loss often have constant ringing. It can be annoying and frustrating.

W&WP: What should one look for when purchasing hearing protection
equipment?

"There are two factors that make noise particularly hazardous in the woodworking industry. The first is the worker's proximity to the noise source, and secondly, the intermittent nature of the noise makes it deceptively hazardous." — Brad Witt

There are a wide range of hearing protection devices available, designed for specific applications and worker preferences. Photo courtesy of Bacou-Dalloz

Witt: OSHA requires employers to provide "a variety of suitable hearing protectors" at no cost to the employee. While "variety" is not specified, it is good practice to include a robust offering. Everyone's ears are different, and one earplug or earmuff style may not be comfortable for the entire workforce. A wide range of hearing protection devices are available, designed for specific applications and/or worker preferences, ranging from dielectric and cap-mounted earmuffs to no-roll foam earplugs that facilitate communication, and banded earplugs that can be quickly inserted during intermittent noise. Employers should offer workers several different styles, including single- and multiple-use earplugs, as well as earmuffs. Also, include a group of workers from different areas in the selection process to improve buy-in and compliance.

W&WP: Are there any steps, other than providing hearing protection to employees, a woodworking company can do to lessen stress on its employees' hearing?

Witt: The first line of defense against noise is to use engineering and administrative controls. Examples include adding mufflers or vibration dampeners, isolating noisy equipment to an enclosed room, or moving dust collection units farther away from workers. It's also wise to implement "buy quiet" policies in the purchase of equipment. But if these controls are not feasible or effective, then hearing protection is our only available option.

W&WP: Will the use of proper hearing protection equipment save a company money in regards to insurance? What, if any, are the penalties a company will face for not following proper procedures in regard to protecting workers from hazardous noise?

Witt: To determine which parts of OSHA regulations were cited most frequently, we reviewed five years of compliance inspections (more than 10,000 citations from 2000 to 2004). We found that the vast majority of offenses were for simply not having a hearing conservation program in place — not doing the basics like noise measurements and audiometric testing. But to be honest, the greatest liability in not having hearing conservation measures in a noisy workplace is not OSHA non-compliance, but rather compensation claims for hearing loss. Insurance carriers recognize and typically reward companies with an effective hearing conservation program in place.

W&WP: What are some things a woodworking company can do to motivate workers to use hearing protection?

Witt: Train all workers, especially new employees, in the hazards of noise exposure, both on and off-the-job. Demonstrate to them the future risk of hearing loss. There are several very good audio demonstrations of noise-induced hearing loss available to play in training sessions. Clearly mark the noise-hazardous areas of your facility. Require compliance from everybody entering that area, including managers and visitors. And try to remove the barriers to wearing hearing protection, by offering a variety of comfortable hearing protectors.