The Washington Post has a story on an under-appreciated, and spreading, public-health issue. The story, which is based on a new report from the Centers for Disease Control and Prevention, is about hearing damage and hearing loss among adults, starting with people in their 20s. The story begins:

Forty million American adults have lost some hearing because of noise, and half of them suffered the damage outside the workplace, from everyday exposure to leaf blowers, sirens, rock concerts and other loud sounds, the Centers for Disease Control and Prevention reported Tuesday.

A quarter of people ages 20 to 69 were suffering some hearing deficits, the CDC reported in its Morbidity and Mortality Weekly Report, even though the vast majority of the people in the study claimed to have good or excellent hearing.

The story goes on to name the sources of the damage, and some of its implications (with emphasis added):

The review's more surprising finding — which the CDC had not previously studied — was that 53 percent of those people said they had no regular exposure to loud noise at work. That means the hearing loss was caused by other environmental factors...

“Noise is damaging hearing before anyone notices or diagnoses it,” said Anne Schuchat, the CDC's acting director. “Because of that, the start of hearing loss is underrecognized.”

The study revealed that 19 percent of people between the ages of 20 and 29 had some hearing loss, a finding that Schuchat called alarming....

Hearing damage results from a combination of volume and the length of the exposure. One minute of hearing a 120-decibel siren can damage hearing, the CDC said. So can two hours of exposure to a 90-decibel leaf blower.

As the National Institute of Deafness has explained, hearing damage of this sort is likely to be cumulative and permanent, since repeated exposure to loud noises lastingly damages the stereocilia, or sensor hairs, inside the ear on which hearing depends. Further NIH information on hearing loss is at this site. The full Post story is worth reading, here. The CDC report itself is here. (Direct link: https://www.cdc.gov/media/releases/2017/p0207-hearing-loss.html)