Clinical characteristics of tinnitus such as duration, consistency and other factors influence the way individuals perceive loudness and annoyance associated with the condition, according to a report in the December issue of Archives of Otolaryngology-Head & Neck Surgery, one of the JAMA/Archives journals. Tinnitus, a ringing, buzzing or whistling sound in one or both ears occurring without outside stimulus, can be acute or chronic, constant or intermittent. Tinnitus can be due to a medical disease or of unknown origin. According to background information in the article, some patients describe their tinnitus to be louder than most or all environmental sounds and 1 percent to 5 percent report that tinnitus is so troublesome that it interferes with sleep or has led to disability and reduced quality of life.