Tinnitus is a condition in which you hear sounds when there is no outside source of the sounds. The sounds can have many different qualities (ringing, clicking, buzzing, roaring, whistling or hissing) and can be perceived as soft or loud. Usually, the person experiencing the tinnitus is the only one who can hear the sounds. Tinnitus can occur either with or without hearing loss, and can be perceived in one or both ears or in the head.