Table 1. Pre- and post-operative air conduction thresholds.

Hz	Mean difference (dB)	p	CI
250	30	<0.001	27.5-325
500	30	<0.001	27.5-32.5
1000	27.5	<0.001	25-30
2000	22.5	<0.001	20-25
4000	15	<0.001	10-17.5