Photo courtesy of theNational Institute on Deafness and Other Communication Disorders
by Daniel Fink, MD, Chair, The Quiet Coalition
Debara Tucci, MD, M.S., M.B.A., Director of the National Institute on Deafness and Other Communication Disorders, issued a statement on February 27 concerning the World Health Organization’s World Hearing Day, which is observed on March 3 every year. In her statement, Dr. Tucci highlighted NIDCD’s “research and initiatives to prevent, detect, and treat hearing loss in the United States and beyond.”
I would hope that among these initiatives is the provision of accurate health education information to the public. Unfortunately, information on NIDCD websites and NIDCD’s Noisy Planet site still contains inaccurate and misleading information about the 85 decibel (dB) sound level. For example, the NIDCD site includes statements like “long or repeated exposure to sound at or above 85 decibels can cause hearing loss” and “[k]now which noises can cause damage (those at or above 85 dBA).” And Noisy Planet says that “[r]esearchers have found that people who are exposed over long periods of time to noise levels at 85 dBA or higher are at a much greater risk for hearing loss.”
As I have written in the American Journal of Public Health, 85 dB without an exposure time limit is not a safe noise exposure level for the public. The difference between an occupational noise exposure level and a possible exposure level for the public was discussed in the NIOSH Science Blog on February 8, 2016.
The NIDCD’s 85 dB “standard” is derived from the National Institute for Occupational Safety and Health’s 85 dBA (A-weighted decibels*) recommended occupational exposure level. This level does not protect all exposed workers from noise-induced hearing loss. The only evidence-based safe noise exposure level to prevent hearing loss was calculated by the Environmental Protection Agency in 1974: a time-weighted average of 70 decibels for 24 hours.
The World Health Organization only recommends one hour at 85 dBA to prevent hearing loss. Mathematically, this is the same as the EPA’s 70 decibels for a day. That’s sound advice!
Unfortunately, because the NIDCD uses 85 dB, this has become the de facto federal standard for noise exposure. It is widely if incorrectly cited by audiologists in media reports and in their online advertising as a safe noise level or the level at which auditory damage begins and is used as a volume limit for headphones advertised as “safe” for children’s hearing, without an exposure time being specified;
I wish Dr. Tucci and NIDCD would disseminate this useful and correct information to the public, rather than continuing to imply that 85 dB is a safe noise exposure level for the public. It just isn’t.