In today’s Science section, a study gauges the risk to hearing posed by use of iPods.

The key to avoiding hearing damage, the researchers say, appears to
be limiting not so much how long one listens to music but how loud it
is played. The study was presented at a recent conference on
noise-induced hearing loss in children.

The researchers, who are
audiologists, concluded that the average young person could listen to a
player at 70 percent of full volume for four and a half hours without
much risk. They also said that if people used the earphones that come
with the devices they could listen to music at an 80 percent level for
90 minutes a day without great risk.

But listening to the music full blast for just five minutes can affect hearing, they said.