How Loud Should Your iPod Be?

How loud should your iPod be? Hearing specialists suggest most iPod users need to dial it back a bit, to prevent hearing loss.

Audiologist Brian Fligor of Boston's Children's Hospital and Harvard Medical School and colleagues worry that individuals listening to their music amidst noisy surroundings are much more likely to raise the volume to risky levels.

The research team estimates that a typical person could safely listen to the iPod for 4.6 hours at 70 percent of full volume using the supplied earphones without greatly increasing the risk of hearing loss.

However, listening to music at full volume through the iPod for more than 5 minutes per day through its stock earphones, they say, could increase the risk of hearing loss in a typical person. These guidelines apply in general to other music players, such as the Sandisk Sansa and the Creative Zen Micro, which they found to produce similar volume levels.

In a separate study, Fligor, along with Terri Ives, of PCO School of Audiology, Elkins Park, Pennsylvania and Cory Portnuff of the University of Colorado observed the listening habits of 100 doctoral students listening to iPods through earphones.

When the students were in a quiet environment, they found that only 6 percent of them turned their players to risky sound levels. When in a noisy environment, a dramatically higher 80% of the students listened to the music at risky levels.

When they used an "in-the-ear" earphone designed to block out background noise, only 20 percent exceeded sound levels considered to be risky. This suggests, Fligor says, that seeking out quiet environments and using "isolator" earphones designed to block out background noise help listeners avoid the tendency to play music at sound levels that can pose risks to their hearing.

"Portable music players are not the only hearing hazard to which kids are exposed," says University of Northern Colorado audiologist Deanna Meinke. "Parents and teachers have to look across exposures for all noisy and loud activities."

Noise-induced hearing loss, she says, can be caused by two types of noise. Sudden bursts, such as firearms and fireworks, can immediately cause hearing loss in children, who are often reluctant to report such exposures to their parents.

The other type is continuous exposure to loud noise, which can damage the ears over time. Sources of continuous noise, she says, including motorized recreational vehicles, loud sporting events, power tools, farming equipment, and amplified music.

For continuous noise exposure such as music, the "level and duration of exposure are important," she says. "It takes repeated exposures over many years to cause a gradual onset of noise-induced hearing loss in both children and adults,� Meinke said.

Since people have many possible encounters with loud sounds, she says, it's important to use safe listening strategies when possible; move away from the noise, turn down the volume or wear properly fitting hearing protection.