Tinnitus refers to sounds heard in the ear or head which are not produced by an external source. It is often described as ringing, buzzing, hissing, whistling or roaring. It may be perceived in one ear, both ears, or centered in the head.
Tinnitus may be constant, occasional or pulsed. The onset may be sudden or gradual. Tinnitus affects as many as 50 million adults nationwide.