The average ABG decreased from 27.5±12.2 dB HL preoperatively to 24.4±14.1 dB HL postoperatively in the T0 group. In the PORP group, the average ABG decreased from 20.5±10.0 dB HL preoperatively to 13.6±11.5 dB HL postoperatively, it decreased from 16.3±13.3 dB HL preoperatively to 13.4±12.0 dB HL postoperatively in the TORP group. Mean improvements in the ABG of 3.1±14.6 dB HL, 6.9±13.1 dB HL, and 2.9±8.3 dB HLwere noted in the T0, PORP, and TORP group, respectively (
Table 2). The difference in mean improvement in the ABG between the groups was not statistically significant (
p=0.211).
The mean thresholds of BC increased 3.6, 3.8, 7.1, 9.3, and 11.6 dB HL at 0.5, 1, 2, 3, and 4 kHz in the T0 group, and by 13.7, 13.1, 9.6, 13.9, and 17 dB HL in the PORP group, respectively. In the TORP group, the mean BC thresholds increased by 2.8 and 3.4 dB HL at 3 and 4 kHz respectively, but they decreased by 3.8, 3.8, and 1.3 dB HL at 0.5, 1, and 2 kHz, respectively. At 0.5, 1, 2, 3, and 4 kHz, the mean thresholds of AC increased by 3.3, 0.3, 1.4, 4.7, and 9dB HL in the T0 group; by 5.4, 3.1, 4.3, 1.3, and 1.3 dB HL in the PORP group; and by 5.9, 6.6, 1.9, 0.6, and 2.8 dB HL in the TORP group, respectively. At 0.5, 1, 2, 3, and 4 kHz, the mean ABG decreased by 0.3, 3.4, 5.7, 4.7, and 2.6 dB HL in the T0 group; by 8.3, 10.0, 5.3, 12.6, and 12.0 dB HL in the PORP group; and by 2.2, 2.8, 0.6, 3.4, and 6.3 dB HL in the TORP group, respectively. The detailed audiologic results of the groups at 0.5, 1, 2, 3, and 4 kHz were shown at
Table 3. In many cases, the BC threshold worsened after CWDM surgery. However, compared to the degree of worsening of the BC threshold, the degree of worsening of the AC threshold was relatively low, and the mean ABG improved at every frequency.