Photo credit: cottonbro studio
by Daniel Fink, MD, Chair, The Quiet Coalition
I’m a big fan of NPR. I usually listen to “All Things Considered” and a few other programs if I’m in the car and I think these programs are among the best on the radio. But in this new report on “All Things Considered,” which aired on Sept. 11, NPR got it wrong. It gave unsound (pun intended!) advice about keeping your ears healthy in a loud world.
The experts speaking in the four minute radio clip provide dangerously incorrect information about safe noise levels. New York City audiologist Ariella Naim and Hearing Loss Association of America executive director Barbara Kelley just provided dangerously inaccurate information about safe listening levels. Naim said, “the rule of thumb is that when you’re listening to a sound at what’s considered 85 decibels, you are safe.” Kelley cited the American Speech Language Hearing Association’s 85 A-weighted decibel (dBA) safe listening sound level. The 85 dBA safe listening standard is the National Institute for Occupational Safety and Health’s recommended exposure limit for occupational noise. The World Health Organization recommends only one hour at 85 dBA to prevent noise-induced hearing loss, but research shows that many young people listen to their music at this level for hours a day.
A-weighting adjusts unweighted sound measurements for the frequencies heard in human speech. The 85 dBA exposure limit does not protect exposed workers from noise-induced hearing loss and it needs to be adjusted downwards for a variety of technical reasons. There is no quick conversion formula from dB to dBA, but using the free NIOSH sound level meter app on my iPhone finds that A-weighted decibels measurements are usually 5-7 dB lower than unweighted measurements. The decibel scale is a logarithmic one, meaning that the 85 dB sound level cited is actually more than double of NIOSH’s recommended occupational exposure limit for noise.
I doubt that anyone in everyday life is exposed to 85 dB or dBA sound for eight hours a day, five days a week for 40 years, but the Centers for Disease Control and Prevention reported that about 25% of Americans age 20-69 have noise-induced hearing loss, most of them without significant occupational exposure. So it’s clear that everyday noise exposure is causing hearing loss in the public, especially in noisy New York City. If people think 85 dB or dBA is safe, I’m pretty sure they expose their ears to much higher sound pressure levels.
What is the safe noise level for the public? As I wrote in the American Journal of Public Health in 2017, the only evidence-based safe noise exposure level is the Environmental Protection Agency’s calculated level of 70 dB time-weighted average for 24 hours. This editorial has been cited 81 times in other peer-reviewed scientific publications. But I think I was wrong. In a paper I presented at the 178th meeting of the Acoustical Society of America last December in Nashville, Tennessee, I postulated that the safe noise exposure level to prevent auditory damage may be as low as 55 dBA.
Regardless of what anyone says — Naim, Kelley or Fink — here is sound advice about keeping your ears healthy in a loud world: Avoid loud noise, turn down the volume, use hearing protection or leave the noisy environment. Because if something sounds loud, it’s too loud and your auditory health is at risk.