It is estimated that one in ten U.S. adults have experienced “tinnitus” during the past 12 months. These people experience ringing in one or both of their ears when there is no external sound present. Tinnitus is not a disease. It is a symptom of a problem in the auditory system. It most often occurs when damage to the hair cells in the inner ear alters the signal that these cells send to the brain. This tinnitus-causing damage may be the result of age-related hearing loss, injury, exposure to very loud noises, certain medications, jaw joint disorders, anxiety, or head and neck trauma. By some estimates, about 75 percent of people with some degree of hearing loss also experience tinnitus.