I. Definition of tinnitus: The subjective sensation of ringing in the ear when there is no external corresponding sound source or electrical stimulation. The characteristics are (1) no external sound source, and (2) a subjective sensation. By definition, there is no distinction between subjective and objective. However, it has been used clinically until now. Objective tinnitus: There is a sound source that can be heard by others, such as myogenic tinnitus and abnormal opening of the eustachian tube sign. Phantom hearing: Only psychiatric patients have phantom hearing, meaningful verbal conversation. Phantom images: Musicians or creative people often have musical sounds in their ears, suggesting mild psychiatric abnormalities. About “chronic” tinnitus: Chronic Tinnitus, duration >1 year; Acute Tinnitus, duration <3 months. Chronic Severe Tinnitus II. Epidemiological Survey of Tinnitus United States (200 million people) China (1.3 billion people) Incidence rate 17% (15%-20%) 34 million 10% 130 million Attendance rate 7% (5%-10%) 14 million 5% 65 million Severity rate 3.5% (2%-5%) 7.0 million 2% 26 million Disability rate 0.8% (0.5-1%) 1.6 million 0.5% 6.5 million Elderly morbidity rate 33% 0.6 million 30% 3.9 million.