System standardization: Results of NH Subjects in SPC and OR
For NH subjects in SPC, the wave V latency at 70dB SPL was 7.305ms, 7.54ms and 8.79ms for S1, S2 and S3 respectively. One-way ANOVA showed statistical difference (p <0.0001). Further multiple comparisons showed no statistical difference between S1 and S2 (p latency=0.77) while both S1 (p <0.0001) and S2 (p= 0.0008) were statistically different from S3 (Figure2A). The fs-ABR thresholds were 31.25, 31.25 and 37.36 dB for group S1, S2 and S3 respectively. One-way ANOVA showed statistical difference (p =0.0033<0.05). Further multiple comparisons revealed that S1 and S2 had no statistical difference (pthreshold >0.99) while the S3 was statistically different from S1 and S2 (Figure2B).
Bland-Altman analysis showed no statistical difference between PTA and fs-ABR threshold for S1 and S2 in SPC (Figure2 C and D). Since the mean bias of S1 group was smaller than that of S2 group, S1 and S3 were chosen for further study in the OR.
For NH subjects in OR, the wave V latencies for group S1 was 7.33±0.39ms, and no statistical difference between wave V latency in SPC and OR was found by two-sided paired t-test (p =0.63>0.01) (Figure2E). Bland-Altman analysis showed no statistical difference between PTA and fs-ABR in OR. The fs-ABR threshold in OR was 37.33dB SPL, 6.08 dB higher than in SPC (p =0.0039<0.01) (Figure2F).