Mashable reports on a study conducted at the University of Leicester that suggests blasting music through ear buds can cause hearing problems:
Many music players can reach levels comparable to that of a jet engine. It is known that noises above 110 decibels can cause hearing problems, including ringing of the ears or temporary deafness — what you may experience after attending a particularly loud concert.
It also is true that many people use ear buds as they do other things that may require attention or the ability to hear outside noises. The best advice: Turn the music down.