Study Populations
In this study, none of the 161 enrolled patients had level 0 or 6 tinnitus. Ninety-six cases were level 3 (59.6%), and 41 cases (25.5%) were level 4. Only three cases (1.9%) were level 1, 16 cases (9.9%) were level 2, and five cases (3.1%) were level 5. To avoid large difference between the groups, we divided all the patients into three groups according to their initial level of tinnitus: 19 were in the mild (levels 1 and 2) group, 96 were in the moderate (level 3) group, and the remaining 46 were in the severe (levels 4 and 5) group. The basic information of the 161 patients at admission is presented in Table 1.