Read before you crank up the volume.

...CBS News medical contributor Dr. Mallika Marshall reports when the volume goes up, so does the risk of hearing loss — dramatically.

Audiologist Brian Fligor of Children's Hospital Boston has found that personal stereo systems, like the iPod, can lead to significant hearing loss. He says there are two critical factors: how loud the music is and how long you listen.

"Noise induced hearing loss develops insidiously," Fligor says.

He tested to see how loud Dr. Marshall likes her music. She was safe at around 80 decibels — or about half way up the dial.

But at decibel levels over 85, Fligor suggests no more than an hour a day with headsets outside the ears — and only 15 minutes with those inside.

"For some types of inner ear phones, most certainly, there is greater potential for danger," Fligor says.

While kids might be the most vulnerable to hearing loss, the generation which included the first Walkman users is now showing some of the worst hearing loss.

As our patients listen to these their MP3 music players for hours each day, unfortunately, hearing loss will increase.