Tinnitus is the perception of sound when no corresponding external sound is present. While often described as a ringing, it may also sound like a clicking, buzzing, hiss, or roaring. Rarely, unclear voices or music are heard. The sound may be soft or loud, low or high pitched, and appear to be coming from one or both ears. Most of the time, it comes on gradually. In some people, the sound may interfere with concentration or cause anxiety or depression. Tinnitus may be associated with some degree of hearing loss. Rather than a disease, tinnitus is a symptom that may result from various underlying causes. A common cause is noise-induced hearing loss. Other causes include ear infections, disease of the heart or blood vessels, Meniere's disease, brain tumors, exposure to certain medications, a previous head injury, earwax, and emotional stress. It is more common in those with depression