NEW YORK (Reuters Health) - The ever-popular earbuds used with many iPods and other MP3 players may be more stylish than the bigger and bulkier earmuff-type headphones, but they may also be more damaging to one's hearing, according to a Northwestern professor.

"No one really knows for sure" the levels at which iPod users listen to music, but "what we do know is that young people like their music loud and seldom worry about any decline in hearing ability," Dean Garstecki, chairman of Northwestern's communication sciences and disorders department, told Reuters Health.

The earbuds commonly used by iPod listeners are placed directly into the ear and can boost the audio signal by as many as nine decibels -- comparable to the difference in sound intensity between an alarm clock and a lawn mower, Garstecki said. Yet, the earbuds do not always fit snugly in the ear, but often allow background noise to seep in, which causes listeners to crank up the volume.

In turning up the volume to drown out background noise, however, people "don't realize they may be causing some damage" to their hearing, Garstecki said.