. "The eardrum aids in hearing and in preventing bacteria and other foreign matter from entering the middle ear.The EardrumCopyright ?? Nucleus Medical Media, Inc.CausesEardrums may rupture from a variety of causes, including:Ear infectionsPuncture from use of a Q-tip or other device inserted in the ear canalDamage to the ear, such as being slapped or hitPressure building up inside the middle ear, as" . . .