by Daniel Fink, MD, Chair, The Quiet Coalition
This article in Popular Science discusses noise-induced hearing loss caused by headphone use.
If headphone volume is high enough to block out noise from traffic or others speaking, it’s probably loud enough to cause hearing loss. If you use headphones or earbuds, that’s an important thing to know.
But also know that the sound levels cited in the article by audiologist Tricia Ashby at the American Speech-Language-Hearing Association aren’t safe. The 85 A-weighted decibel standard she mentions is an occupational noise exposure standard that even with limited exposure–8 hours a day, 250 days a year at work, for 40 years in the factory–allows 8% of workers to suffer “excess” hearing loss.
Noise is different from other occupational exposures, e.g., toxic solvents or ionizing radiation, because we are exposed to noise all the time, all day long, all year long, for an average whole lifetime now approaching 80 years.
As I wrote in the American Journal of Public Health, the only evidence-based noise exposure level to prevent hearing loss is a time-weighted average of 70 decibels for 24 hours. I discussed the reasons why even 70 decibels is probably too loud in this blog post for the AJPH. Well, just two hours exposure to 85 decibel noise makes it mathematically impossible to average below 70 decibels for the day.
Ms. Ashby is correct that a recent study reported a declining prevalence of hearing loss in American adults, but the Centers for Disease Control reported that 25% of American adults have hearing loss, many without any occupational noise exposure.
I have been predicting an epidemic of noise-induced hearing loss in young people using headphones, and now the preliminary evidence is beginning to appear in scientific journals.
