Another Thing to be Afraid Of

Yesterday’s Wall Street Journal (link requires registration) ran an article on the potential danger of hearing loss from prolonged use of iPods and other portable music players. When imprudent young people crank up the volume, the hair cells in the inner ear could be damaged (no, pops, the hair growing out of your ears is not what we’re talking about here).

There are two ways that noise exposure leads to hearing damage. Brief exposures to extremely loud sounds, like gunfire, can cause permanent damage. But consistent exposure to even moderate-level loud sounds wears out the hair cells in the inner ear, which are responsible for acute hearing abilities. When these cells are damaged by noise exposure -- like a loud concert -- they typically recover after two days of rest. With repeated exposure to loud sounds, however, the hair cells' ability to recover weakens. Eventually the hair cells die, leading to permanent hearing loss.

The researchers determined that the exposure limit for safe headphone listening is one hour a day with the volume no higher than 60%. If you listen for more than an hour, you should turn the volume below 60%. Another informal rule of thumb: If you have to remove the headphones to hear people talking to you, it is too loud.

Chart courtesy of Wall Street Journal.

Soon to come as night follows day: warning labels on earbuds and iPods.