Even moderate noise may harm hearing
Chronic, low-level sound exposure causes deficits in rats
Constant low-level noise might cause hearing problems, a new study in rats finds. The discovery, published online May 15 in Nature Communications, suggests that extended exposure to noise at levels usually deemed safe for human ears could actually impair sound perception.
The findings are “definitely a warning flag,” says study coauthor Michael Merzenich, an integrative neuroscientist at the University of California, San Francisco. He adds that it will be important to find out whether people employed at factories where continuous low-intensity noise is emitted throughout the workday experience similar consequences.
“The big picture is that there is no safe sound,” says Jos Eggermont, an auditory neuroscientist at the University of Calgary in Canada. Even sounds considered safe can cause damage if delivered in a repetitive way, he says. “There might be not-so-subtle effects that accumulate and affect communication and speech understanding.”