Fig. 3.

Hearing thresholds were measured 2 weeks after noise exposure (NE), and threshold shifts from baseline were calculated. (A) Hearing thresholds among the different groups varied 2 weeks after NE. Significant differences were found between the OP-only and the estrogen replacement therapy groups at all test frequencies. (B) The threshold shifts between baseline and 2 weeks after NE varied among all groups. In addition, the threshold shift data between the OP-only and the estrogen replacement therapy groups differed significantly at all test frequencies. At 16 kHz, there was also a difference between the sham OP and ET2 groups. Error bars indicate standard deviation. SPL, sound pressure level; OP, ovariectomy; ET1, low-dose estrogen replacement therapy; ET2, high-dose estrogen replacement therapy. ^*P<0.05, ^**P<0.01.