Table 2: Bone conductance threshold measured by pure tone audiometry in controls.

Frequency (Hz)Mean threshold value
Before treatment (SD)One month after treatment (SD)

2508.9 (1.1)9.3 (1.0)0.94
5008.5 (0.9)8.9 (0.7)0.87
10008.7 (0.7)8.1 (0.3)0.48
20009.1 (0.8)8.8 (0.9)1.10
40008.9 (0.9)10.1 (1.1)0.23
800011.2 (1.4)10.9 (1.8)0.89

SD: standard deviation.