Table 1.

Pre and postoperative thresholds of air and bone conduction, air-bone gap, and SRI. Group I - Teflon.

Frequency (kHz)	N	Preoperative	Postoperative	Difference	P†
Air conduction
0,25	64	65,55 ± 13,25	36,25 ± 23,13	29,30 ± 21,21	<0,001
0,5	64	65,23 ± 12,03	35,55± 24,43	29,69 ± 22,14	<0,001
1	64	62,97 ± 12,59	35,63 ± 23,44	27,34 ± 22,73	<0,001
2	64	57,97 ± 14,13	36,95 ± 23,10	21,02 ± 23,64	<0,001
3	62	58,39 ± 15,93	36,94 ± 24,40	21,45 ± 25,90	<0,001
4	64	60,55 ± 19,25	44,06 ± 24,57	16,48 ± 26,75	<0,001
6	64	61,72 ± 18,54	52,27 ± 26,53	9,45 ± 26,93	0,03
8	63	60,24 ± 20,78	57,94 ± 27,79	2,30 ± 27,00	0,157
Mean values1	62	61,07 ± 11,93	35,89 ± 22,59	25,18 ± 22,53	<0,001
Bone conduction
0,5	63	21,11 ± 9,65	21,83 ± 14,90	-0,71 ± 14,48	0,532
1	64	28,36 ± 9,04	22,89 ± 14,96	5,47 ± 14,13	<0,001
2	64	31,80 ± 13,64	28,91 ± 16,94	2,89 ± 14,66	0,011
3	63	31,90 ± 13,12	28,89 ± 17,86	3,02 ± 17,24	0,023
4	64	28,59 ± 14,76	31,41 ± 19,67	-2,81 ± 18,30	0,685
Mean values1	62	32,08 ± 13,22	29,95 ± 15,01	2,56 ± 13,57	<0,001
Air-bone gap2	60	32,77 ± 8,05	10,88 ± 12,47	21,90 ± 14,85	<0,001
SRI Vocal audiometry3	60	62,67 ± 13,16	40,33 ± 21,13	22,33 ± 22,45	<0,001

The data represent mean ± standard deviation, in decibels.

^†Significance level (Student t test for paired samples) of air and bone conduction threshold differences.

¹Mean values among the frequencies of 0.5, 1, 2 and 3 kHz. When not available, the 3kHz threshold was replaced by the arythmetical average of the 2 and 4 kHz frequencies.

²Difference between the air and bone conduction mean values.

³Speech Recognition Index.