Young people play their iPods so loudly, and listen so much, that audiologists predict widespread hearing loss among members of the next generation.
But older people use portable listening devices too, and they also face a risk.
With age, we become less able to recover from insults to the body, including damage to the delicate, hair-like fibers deep in the ear that transmit sound vibrations to the brain. Once damaged, those hair cells never recover.
When listening to a portable in a noisy environment, we may turn up the volume to an unsafe level but not recognize the danger because we feel no pain.
"I have a young patient who has a significant noise-induced hearing loss," said Dr. Brian Fligor, director of Diagnostic Audiology at Children's Hospital in Boston. "He's a construction worker, exposed to loud noise all day long, but instead of using the earplugs, he listened to music through headphones."
The hair cells in our inner ear are equally damaged, however, whether we like the sound or not.
Fligor has just completed research that suggests a way for young and old to listen more safely to portable devices.
He asked test subjects to listen to music through various headphones, telling them to set the volume to the level they prefer. Then he added background noise - for example, the roar of the engines recorded in an airplane.
The people listening through typical "earbud" headphones such as those that come with an iPod turned up the volume to an average of 88 decibels - significantly above the 85 decibels considered the upper limit of "safe" listening.
Those who listened through "isolator" earphones, however, such as the ER6i in-the-ear headphones by Etymotic, turned up the volume to an average of only 73 decibels.
Sound-isolating earphones range from inexpensive foam earbuds that resemble earplugs to elaborate, over-the-ear "noise cancellation" headphones that sell for hundreds of dollars.
Freelancer Tom Valeo writes about medical and health issues. Write to him in care of Pulse, St. Petersburg Times, P.O. Box 1121, St. Petersburg, FL 33731, or e-mail email@example.com.
The cost of quiet
Quality and price for noise-canceling or sound-isolating earphones vary widely. Here is a sampling of products, without shipping:
- Plane Quiet NC-7 headphones, $80.
- Sennheiser PXC 300 headphones, $128.
- Shure E4C in-ear headphones, $179.
- Bose QuietComfort 3, $349.
For an easy-to-understand discussion of the technology, and review of several products, go to www.thetravelinsider.info and click on Road Warrior Resources, then Noise Reducing Headphones.