Tinnitus, also common in older people, is the ringing, hissing, or roaring sound in the ears frequently caused by exposure to loud noise or certain medicines. Tinnitus is a symptom, not a disease, so it can accompany any type of hearing loss.

Tinnitus can also be a sign of other important health problems, such as allergies and problems in the heart and blood vessels. Tinnitus can come and go, or it can persist or stop altogether.

Source: National Institute on Aging, U.S. National Library of Medicine