3.2 Postoperative hearing
Prior to surgery, all seven patients experienced a reduction in conductive hearing or a reduction in mixed hearing that was primarily conductive in nature. The preoperative pure-tone average values for air conduction (AC), bone conduction (BC), and the air-bone gap (ABG) were 60.2 dB, 25.5 dB, and 34.8 dB, respectively. Postoperative hearing tests were conducted between 3 and 6 months for all patients following the operation. The preoperative and postoperative hearing of the seven patients did not differ significantly. Among the two patients with lateral semicircular canal fistulas that were treated by patfching or filling, one patient showed postoperative improvement in hearing, while another patient experienced a further reduction in hearing. Table 2 shows the preoperative and postoperative hearing threshold values of the seven patients.