The transmission of external sound to human ears and finally to auditory cortex depends on the following three links: first, impedance matching of sound transmission structure in middle ear; Second, the auditory receptors in the inner ear convert acoustic energy into nerve impulses; Third, the nerve conduction from the cochlear nucleus to the auditory cortex of the collar lobe is smooth. If any one of these three links fails, tinnitus will occur. From etiology and anatomy, tinnitus can be divided into subjective tinnitus and objective tinnitus.