The wail of sirens, buzz of power tools, and blast of high-pressure fire hoses contribute to high levels of intermittent noise exposure for firefighters on the job. Still, adoption of hearing protection devices (HPDs) remains low in this group, with firefighters using HPDs only 34 percent of the time that they're needed, reported a study published in the Journal of Occupational and Environmental Medicine (2013;55:960-965).
In the study, 42.6 percent to 49.9 percent of firefighters had hearing loss in the noise-sensitive frequencies of 4 and 6 kHz, reported the researchers, who were led by OiSaeng Hong, RN, PhD, of the University of California, San Francisco, School of Nursing. Firefighters who had hearing loss were significantly less likely to use hearing protection devices compared with those who had normal hearing—18.1 percent and 34.9 percent, respectively.
The longer the career in fire services, the more severe the hearing loss. In addition, about 13 percent of participants showed asymmetrical hearing loss, with significantly worse hearing in the left ear than the right.
“The results are clear that noise-induced hearing loss is caused by repeated exposure to loud noise, but whether the situation will change with more sophisticated technology, mandates from departmental administration, and a greater level of education remains to be answered,” said senior author Daniel Samo, MD, medical director of health promotion and corporate services at Northwestern Memorial Physicians Group.
“There's not really much regulation from the departments requiring that firefighters use protective devices, although I'm sure some recommend it. It's therefore important that larger longitudinal studies be conducted in order to track any changes in behavior.”
The New York City Fire Department (FDNY) currently measures the hearing of all its members at medical moni-toring visits, department representative Frank Dwyer said in an e-mail to The Hearing Journal.
“For special operations, our members often use hearing protection—for example, below deck on our fireboats in the engine room—and the Department also issues earplugs for large-scale events and for testing of special equipment.”
REVIEWING THE DATA
Dr. Hong and colleagues recruited 722 firefighters from occupational health clinics, fire departments, and audiologists' hearing test clinics in California, Illinois, and Indiana. Of the 722 firefighters, 425 participated in the study, completing a web-based survey and standard pure-tone audiometric testing.
The median age was 45, and the median length of time working in fire services was 16 years. About 85 percent of participants said that they were exposed to loud noise at work on a daily or weekly basis, and 91 percent recognized that hearing loss could contribute to work-related injuries or safety problems.
There's no question that firefighters are exposed to high levels of sound from time to time on the job, but it's unlikely that sources like air horns and sirens are a cause for noise-induced hearing loss, countered William Clark, PhD, director of the Program in Audiology and Communication Sciences at the Washington University School of Medicine in St. Louis.
“This study tries to make the connection, but it needs to pay attention to workplace sound exposure levels based on an eight-hour workday,” he said.
“There are several limitations in this study. My main disappointment is that the potential value of its findings was largely obscured by the way their data were grouped and presented, and the conclusions resulting therefrom.”
“Nevertheless, this study is important because it has great data, and it's a motivator to analyze more data from fire departments.”
ADVANCEMENTS IN TECHNOLOGY
Although it's difficult to come up with an exact number of how many firefighters have hearing loss because the condition can be quantified in different ways, this study is strong because of how big and broad it is, said Deanna Meinke, PhD, professor of audiology and speech language sciences at the University of Northern Colorado in Greeley.
“The data looks to have been collected in a viable way, and the hearing test used seems to be indicative of a true field study.”
“An interesting part of the study comes when you get to the discussion part, and they go over why firefighters may not want to wear protection. What it comes down to is that when they put these things into their ear, they're artificially creating a hearing loss. We really need newer technology for firefighters because an earplug just can't be the best option.”
Advancements in design, such as the integration of devices into a firefighter's uniform, could be a big move forward in changing attitudes toward hearing protection devices, Dr. Samo agreed.
“Devices are being developed that will only block out very high levels of noise, protecting the firefighters from any damage while allowing them to efficiently do their job,” he said.
“You don't want to impair your hearing any more than it already is because you lose a lot of senses when you enter a fire; you want to be able to hear the crying baby and then find the baby”.
“I think change is inevitable. When you're dealing with such a large cultural change in behavior, it will be a slow process, yet one that's worth waiting for.”
HJ Return to thehearingjournal.com