Tinnitus (pronounced TINN-uh-tus or tinn-I-tus) is a ringing or roaring sound that you hear in your ears when the sounds don't exist. Only you hear your tinnitus. Sometimes it's very loud and constant, and sometimes it comes and goes. It is caused mostly by being exposed to loud noises (rock concerts, playing in an orchestra or on-the-job noise), but it can be a sign of underlying disease or reaction to a drug. There is no known cure for tinnitus, but there is good news about upcoming treatments.