Photo credit: Pixabay
by Daniel Fink, MD, Chair, The Quiet Coalition
A new report in The Lancet: Regional Health Americas found that in the United States, rural residents had worse hearing than urban residents. The goal of the research was to create estimates of hearing loss at the state and county levels. The study was led by researchers at the University of Chicago’s NORC, a nonpartisan social research organization.
The research relied on audiometry results collected over several years by the Center for Disease Control and Prevention’s National Health and Nutrition Evaluation Survey, diagnosis data from 2019 Medicare payment claims, Social Security Administration data about disability payments and U.S. Census Bureau data. Software was developed for small area analysis of this data.
To me, the findings were counterintuitive. New York City, the “city that never sleeps”, has long been considered one of the noisiest cities in the world. As a result, many assume that hearing loss in big cities is common because of the high levels of noise exposure. Studies substantiated high levels of noise exposure in NYC. But new research found that a greater percentage of people living in rural counties had more significant hearing loss than those in urban areas. At the state level, West Virginia, Alaska, Wyoming and Arkansas had the highest rates of hearing loss. Washington D.C., New Jersey, New York, Maryland, and Connecticut had the lowest.
In an NPR interview, study co-author Nicholas Reed, an audiologist at Johns Hopkins University’s Bloomberg School of Public Health, pointed out that we commonly think of rural areas as being quiet, but they’re not. Reed pointed out that common jobs in rural areas — like farming, mining and logging — exposed workers to high levels of occupational noise. Recreational activities also found primarily in rural areas (snowmobiling, dirt biking and hunting) were also noisy. On top of increased noise exposure, hearing health care can be hard to find in rural areas.
Reed spoke about the need for prevention of noise-induced hearing loss, and building awareness about the issue. Unfortunately, he misquoted both the Occupational Safety and Health Administration’s permissible noise exposure level and its safety for the public. It’s not 80 decibels, and one can’t be exposed to 80 decibel sounds for eight hours without risking auditory damage. OSHA’s permissible occupational noise exposure level is 90 decibels, and that isn’t safe for hearing. It allows a 25% excess risk of hearing loss, and that certainly isn’t safe for the public.
The only evidence-based safe noise level for hearing is the EPA’s 70 decibel time-weighted average for a day. But, the actual safe noise level may be as low as 55 A-weighted decibels for a single exposure and 55-60 decibels for a day. A-weighting adjusts sound measurements to approximate the frequencies heard in human speech.
I usually don’t bother trying to correct audiologists who don’t understand what safe noise exposure levels are, but I will reach out to Reed and send him information about this. I’m glad he also thinks about prevention rather than treatment, and public education about what’s safe and not safe. But I also think people who have expert knowledge relevant to public health need to get their facts straight.
Preventing noise-induced auditory damage, which also includes developing tinnitus and hyperacusis, is easy. Avoid loud noise, turn down the volume, leave the noisy environment or use hearing protection. If people know what safe noise levels are, and how easy it is to prevent noise-induced hearing loss, perhaps they will protect their hearing and that of their children and grandchildren.
