Years of playing in rock bands as well as attending concerts have put a strain on my hearing, which is often a good excuse for not hearing orders from my wife or coworkers. Auditory damage is well documented, and OSHA requires hearing protection for people working in loud noise environments. In its literature, it clearly states this: “Exposure to high levels of noise can cause permanent hearing loss.” And neither surgery nor a hearing aid can help to correct this type of hearing loss.
|The DI15 Electronic Earplug.|
Short-term exposure to loud noise can also cause a temporary change in hearing or tinnitus. OSHA sets a permissible exposure limit on workplace noise, which is 90 dB during an 8-hour day. The National Institute for Occupational Safety and Health recommends that “all worker exposure to noise be controlled below a level equivalent to 85 dB for 8 hours to minimize occupational, noise-induced hearing loss.” It suggests that noise levels be controlled or if not possible that “hearing protection devices such as earmuffs and plugs be considered as an acceptable but a less desirable option.”
How does this relate to the dental practice? For one thing, the noise of the handpiece (the greatest offender) is not continuous for 8 hours a day, so there is no real requirement; however, studies do point to dental professionals being affected. I have been talking with Sam Shamardi, a Boston-based periodontist who has been studying this issue for several years. He states, “Noise-induced hearing loss is permanent and irreversible and nearly a guarantee to some degree for all dental professionals. Noise, like smoking or sun exposure, is a cumulative and additive process, so even shorter exposures below industry standards during our workdays will accumulate during time to cause serious damage.
“The dental literature and the ADA as early as 1974 clearly show our environment causes damage—handpieces, suctions, ultrasonics, lab equipment, and even solvents can contribute to hearing loss and other significant systemic health issues. And we are doing nothing to protect ourselves.
“Noises we are exposed to at work each day are louder than we perceive. The shrill of the suction and high pitch make us cringe, and we all directly or indirectly know colleagues with tinnitus and hearing damage, yet we have never thought to ask why.
“The dental literature is saturated with disturbing statistics. Dental professionals consistently are found to have poorer hearing at the standard 3- and 4-kHz levels compared to other health professionals of similar age/gender (source: Ahmed, Tolentino, and Gurbuz). Rytkonen and Baren found that ultrasonic noise levels for the high-speed handpiece reach can 89 dB, with ultrasonic scalers and high-speed air turbines reaching 107 dB and 115 dB respectively. Folmer showed different high-speed handpiece brands reaching ranges of 90 dB to 115 dB, while Wilson showed hygienists utilizing ultrasonic instruments having ‘significantly worse hearing thresholds compared to non-users.’ And Lehto’s 15-year follow-up study showed significant high frequency hearing loss in both ears for both genders across all age groups.”
One might think that simple devices such as small sponges placed in the ears should reduce noise levels. There are also several products in the marketplace that act as baffles, which reduce the amount of sound that comes into the ear. However, this also comes with the muffling of sounds, and this is not really desirable, for example, when speaking to the chairside assistant or listening to a patient. Some may think that noise cancelling headphones could be an answer. There are a number of negatives. They cancel all external sounds including familiar noises of instruments being used as well as some outside voices—not a good thing for inter-office communication. Also, the better devices are oversized ear-covering headphones, which would surely be in the way. Dr. Shamardi has devised a better, more high-tech solution—he has developed the DI15 Electronic Earplug. He explains: “The DI15 is revolutionary for our field and the only product of its kind. Unlike foam or filters, which significantly muffle sounds and compromise communication with patients and staff, the DI15 uses a high-tech microcircuit developed in the United States that allows for all sounds to be heard 100% naturally, with no distortion, despite having a sealed, plugged ear. At the same time, noises in the high frequency/decibel range are specifically targeted and instantly compressed to safe levels. The result is an environment where communication is not compromised, and hearing damage is prevented.”