Huh? What did you say?
April 10, 2005
Limit loudness and length of headphone use to prolong good hearing
Emily Snyder remembers reading once about the risks headphones have to her hearing.
“I read a pamphlet about it that came with one of my headphones,” the sophomore education major said. “I don’t remember; it wasn’t very important.”
Snyder, who listens to her iPod through the Apple-issued earbud headphones, is more informed than many young people are about the risks: She at least knows there is a risk.
John Hawks, associate professor of audiology, said any type of headphones could pose a risk to hearing, not just the ones that you insert in your ear.
Although damage is usually reversible, young people are more likely to damage the hair cells in the inner ear, he said.
“It’s really your hardcore users — the people who spend hours a day under their headphones — that are at risk,” Hawks said.
He said he’s never seen a student come in because of hearing loss due to headphones.
“It’s hard for kids and young people,” he said. “(You are) not likely to damage your hearing enough to come see me, but at 30, you might have the hearing pattern of a 50- or 60-year-old.”
The risk is based on volume and length of time one is exposed to the noise.
“If you’re using a personal sound system, and I’m standing next to you and I can hear it, that’s probably too loud,” Hawks said.
The specific volume would vary by song and the specific unit and headphone combination, he said. Because music isn’t a continuous signal, the loudness of the sound can vary by as much as 40 to 45 decibels, it is difficult to say what the loudness is and how long is safe.
But a 2004 study by researchers at the Sargent College of Health and Rehabilitation Sciences at Boston University found that using regular headphones with the volume at 70 percent for one hour was the maximum “noise dose.” The study also found that using insert headphones decreased the volume level it was safe to listen to.
Carol Sommer, the clinical director for the School of Speech Pathology and Audiology, said in-ear style headphones could cause more damage than regular headphones.
“The closer you go to your ear drum, and the longer you listen, what might not damage your hearing with regular headphones could,” Sommer said.
Most players are capable of putting out 120 decibels, Hawks said.
“There’s no regulation over those devices,” he said. “Without a government mandate, it’s up to a manufacturer to decide.”
The Occupational Safety and Health Administration regulates noise levels on the job, so workers exposed to noise above 85 decibels for eight hours must be provided ear protection, Hawks said.
“Eighty-five decibels is not terribly loud,” Hawks said. It is about the level of a person shouting or a loud car radio.
Hawks said for every five decibels above 85, the amount of time a worker can be exposed without protection goes down by half.
“Basically, there’s a trading relationship,” he said. “The louder you go, the shorter you can expose yourself to it.”
Most people don’t appreciate their hearing until they start to lose it, Hawks said.
“Ears don’t turn black and blue, don’t break like a bone, don’t bleed like a nose…” Hawks said. “There are no outward, visible signs or symptoms of damaging your hearing until it’s too late.”
For now, Snyder still isn’t worried.
“I don’t listen to it that loud,” she said. “If I do, it’s not all the way up or very often, so I don’t worry about my hearing.”
Contact technology reporter Meranda Watling at [email protected].