Noise is bad for health, study finds

A decibel reading taken at a restaurant in Winter Park, Fla., shows a high noise level. Research suggests children exposed to constant loud noise do poorly in school.
A decibel reading taken at a restaurant in Winter Park, Fla., shows a high noise level. Research suggests children exposed to constant loud noise do poorly in school. (JOSHUA C. CRUEY / Orlando Sentinel / MCT)
Posted: December 03, 2013

Noise is so ubiquitous you might not even notice that you've forgotten what silence sounds like.

There are sirens, buses, planes, squealing brakes, and hostile horns if you frequent the city, and lawn mowers, leaf blowers, snow blowers, and over-vigilant dogs if you don't. There's whatever you're blasting through your ear buds, voices from the next 12 cubicles over, jarring cellphone ring tones, the television, children screaming, roaring sports fans, restaurants so loud you have laryngitis when you leave, snoring.

"You have noise everywhere," said Mathias Basner, a University of Pennsylvania professor who thinks much more deeply about sound than most of us. "Our lives are full of noise."

You might see all that as a sometimes irritating, sometimes exhilarating part of life.

Basner sees it as something else: a public health problem.

He led a review of recent noise research for the Lancet medical journal. His team concluded evidence is mounting that exposure to noise - at work, in the environment, and in social settings - not only causes hearing loss but can result in annoyance (sometimes considered a health problem, Basner said), poor sleep quality, learning problems for children, high blood pressure, and cardiovascular disease.

Basner, an assistant professor of sleep and chronobiology whose work focuses on airport noise, said some of the negative effects stem from how our bodies respond to sounds that could signal danger.

"The auditory system has kind of a watchman role," he said. "It's always open. It's always awake. It's constantly checking for environmental threats."

When we're exposed to high levels of noise, he said, it creates a stress response. That leads to the release of hormones associated with higher blood pressure and cardiovascular disease. You can't prove that high levels of noise cause these problems, Basner said, but studies have shown noise exposure is associated with increased risk.

Certain sound levels cause physical damage to the auditory system, but Basner said much of what we call noise is more subjective. A fan might find high-volume Imagine Dragons pleasurable (it could still be ruining his or her ears) while a neighbor could find it highly unpleasant. The office conversation about the concert might not be loud enough to damage eardrums, but it might trigger stress hormones anyway if it makes focusing on a difficult project hard.

The Lancet report found that multiple studies showed a connection between environmental noise and children's learning problems. Children exposed at school to aircraft, road, and rail noise performed worse on tests of reading and memory and standardized tests than those in quieter schools.

Basner's team from the International Commission on Biological Effects of Noise also highlighted hospital noise levels, which are twice as high as they were in the 1960s and about four times as high as the World Health Organization recommends. "Hospital noise could therefore be an increasing threat to patient rehabilitation and staff performance," they wrote.

Many hospitals have recognized the problem and are working to reduce noise. Basner said alarms and telephones, which are designed to get the attention of staff, are most likely to interfere with patients' sleep.

Getting good-quality sleep is important, Basner said, because certain physiological processes are meant to occur at night, during sleep. If sleep is disrupted, key processes could be disrupted as well.

"The body needs some quiet periods," he said, "and the most important one is at night."

Basner, who has a grant from the Federal Aviation Administration to study the impact of airport noise, said noise should be regulated and children and adults should try to avoid noise.

He said his classic example of how to reduce environmental noise is the leaf blower, an extremely noisy device easily (he thinks) replaced by very quiet rakes. No one needs to tune motorcycles so they're louder. People who live in noisy neighborhoods might help themselves by sleeping in a quieter bedroom at the back of the house rather than in one that fronts the street.

What about noise in the bedroom - room-rattling snoring from the person you married? "That's not a good thing, either," Basner said. He said one study showed having a partner who snored and changed position often was almost as bad as being barraged by airport noise. Another found some women lost hearing in the ear that was usually closest to their snoring mate's side of the bed.


sburling@phillynews.com

215-854-4944

@StaceyABurling

www.inquirer.com/health_science

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