BY CHRIS BLAND
The fire service has made great advances in safety since I became a firefighter. Our personal protective equipment has improved tremendously over the past several decades. Additionally, a dramatic cultural shift has made it the norm to always wear our safety gear, even on the mundane calls. In spite of these advances, however, we have not focused on a very important aspect of personal safety: protecting our hearing. This passiveness toward hearing conservation occurs across many agencies and all ranks. I am a man on a mission to protect our hearing.
Adequate hearing is important so firefighters can understand spoken commands over the radio while wearing self-contained breathing apparatus (SCBA) as well as hear evacuation and air alarm signals. An inability to hear low-intensity sounds or to distinguish a voice from background noise could lead to a failure to respond in a situation of immediate danger.1 Your life, the life of your fellow firefighter, or the potential rescue of a victim could depend on your hearing.
HEARING PARAMETERS
It seems that we have become acclimated to noise generationally. Everywhere we go, there are personal music players and cell phones. Often, we fail to realize how easily we can severely and permanently damage our hearing. A 2012 study by the University of Leicester found that noise from earphones and headphones on personal music players can reach noise levels equivalent to those of jet engines. The researchers observed underlying auditory cell damage from these loud exposures.2 The sounds we hear and their intensity are measured in decibels. An increase of 10 decibels represents a tenfold increase in power, and a 20-decibel increase reflects an increase 100 times more powerful. The National Institute for Occupational Safety and Health reports that repeated exposure to sound above 85 decibels can cause serious and irreversible hearing damage.3 As firefighters, we regularly encounter sounds well above 85 decibels. Class A sirens emit 120 decibels within a 10-foot radius, and chain saws can reach 125 decibels. Noise-induced damage from these exposures accumulates throughout our life, and when volumes exceed 125 decibels, safe exposure durations may be measured in seconds.
Doctors Paul Pepe, James Jerger, Robert Miller, and Susan Jerger studied a group of 192 firefighters in a busy urban emergency medical services system and found the rate of hearing loss over time was 150 percent of that expected in age-matched nonnoise exposed individuals.4 A 2005 study in Montgomery County, Maryland, found 15 percent of the county’s 1,038 firefighters have some hearing loss, and a third of those had moderate to severe impairment.5 Hearing loss has a huge impact on the fire service, and we must do more to protect our hearing.
Hearing conservation begins with understanding how our ears work. We perceive sound when sonic pressure waves strike our eardrums and pass through the structures of the middle ear to rows of tiny auditory hairs in the inner ear. These hairs vibrate in response to sound and dispatch electrical impulses to the brain. Auditory hairs are extremely sensitive and are readily damaged by the violent vibrations of intense sound, infection, and certain antibiotics, similar to the way blades of grass are bent over by a strong wind. The damage to these hairs is permanent; they do not grow back. With noise-induced hearing loss, a condition known as tinnitus often follows. Tinnitus is a constant hum or high-pitched ringing in the ears. When the hairs of the inner ear are damaged and stop transmitting, the brain turns up the volume control to try to hear the very weak or nonexistent signals. Tinnitus may be triggered by even a single intense noise exposure. I can recall the day and the hour of the emergency incident when a single loud exposure led to a ringing in my ears that has never gone away.
STANDARDS
Hearing standards for firefighters are addressed in National Fire Protection Association (NFPA) 1582, Standard on Comprehensive Occupational Medical Program for Fire Departments. To safely perform under emergency conditions, the NFPA recommends that firefighters not have a hearing loss in their unaided (better) ear of greater than 40 decibels averaged at 500 Hz, 1,000 Hz, 2,000 Hz, and 3,000 Hz during audiometric testing. (1)
Any time we have to raise our voice to be heard, we are in a potentially hazardous environment for our ears and hearing. The very nature of our profession places us in these hazardous sound environments quite regularly. Therefore, we must be proactive in protecting our hearing.
HEARING PROTECTION
To reduce our chance of hearing loss, we should always carry ear plugs in our turnouts and use them. Whenever we are in an extreme sound environment, we need to wear hearing protection. We would not enter an immediately dangerous to life or health environment without our turnouts and breathing apparatus. Likewise, we should not enter an immediately dangerous to hearing environment without hearing protection. Quality ear protection allows you to hear sounds, just at lower volumes. Use foam, silicone, or premolded ear plugs that fit snugly into your ear canal. Look for products with noise-reduction ratings of 22 decibels or greater. Always use hearing protection during training operations that involve apparatus drafting and pumping, chain saws, positive pressure fans, and sirens. Keep windows up in your apparatus while responding, wear a sound-attenuating headset in the cab, and turn off the siren when you don’t need it. If your apparatus siren is mounted on the top of the cab, have it moved to the front bumper. If your agency does not have a hearing conservation program in place, speak to your safety officer about implementing one. We must advance a culture of hearing protection at all levels of our organizations.
We live in a wonderful world filled with a multitude of sounds that can lift us up when we are down and make us dance on our feet. Enjoy the amazing variety of sounds that life has to offer, but be vigilant in hazardous sound environments and protect your hearing.
References
1. National Fire Protection Association. International Codes and Standards Organization, (2013). NFPA 1582, Standard on comprehensive occupational medical program for fire departments. (6.5.1-2; 1582-11, 42)
2. University of Leicester. “Earphones potentially as dangerous as noise from jet engines, researchers find,” Science Daily. Aug. 29, 2012. Retrieved April 16, 2013, from www.sciencedaily.com/releases/2012/08/120829064707.htm.
3. U.S. Department of Health and Human Services, National Institute for Occupational Safety and Health. (1998). Occupational noise exposure; 1:1.
4. Pepe PE, Jerger J, Miller RH, and Jerger S. “Accelerated hearing loss in urban emergency medical services firefighters,” Annals of Emergency Medicine; 1985, (v14:5), 438-442.
5. Roylance FD, “Firefighters sue siren manufacturer over hearing loss.” Retrieved from www.baltimoresun.com/news/nationworld/balte.hearing04dec04,1,7182803.story?page=3&coll=bal-nationworld-headlines; Dec. 4, 2005.
● CHRIS BLAND is a captain with the Alameda County (CA) Fire Department and a 21-year veteran of the fire service. He is a California-certified fire instructor, fire officer, fire inspector, and hazardous materials specialist. Bland has a fire technology degree from Mission College and a bachelor’s degree from San Jose State University.
Enter 124 at fireeng.hotims.com
Fire Engineering Archives
