The production of earwax is a little noticed bodily function-and, frankly, that is the way most people prefer to leave it.

But despite its rather useful way of trapping particulate matter and stopping it from moving deeper inside the ear, earwax can build up in amounts large enough to impair hearing.

Dale Rice, M.D., chair of the Department of Otolaryngology and the Leon J. Tiber and David S. Alpert Chair in Medicine at the Keck School of Medicine of USC, says that most people shed earwax - also known as cerumen - as routinely and imperceptibly as they shed skin.

But for others, the special sweat glands in the ear canal produce the sticky wax faster than the body's self-cleaning mechanism removes it. The resulting buildup can cause earaches, a sensation that the ears are plugged and hearing loss, he says.

Rice says that the most common method of cleaning the ears - using cotton swabs to dislodge the wax-is probably the most dangerous, promoting infection and accidental damage to the ear's structures. He also cautions that earwax should be removed only by a physician if there is ear pain, discharge, a suspected ruptured eardrum, prior ear surgery or tubes in the ears.

"There are self-treatments such as softening the wax with warm mineral oil and over-the counter products," he says. "But it is best to first let your physician determine if you have excessive earwax, then proceed with a treatment."