Group

Type of Tympanoplasty

No. of

ears

M/F

Age mean (years)

(range)

Pre-operative ABG mean (dB)

(range)

Post-operative ABG mean (dB)

(range)

ABG Gain mean (dB)

A

Type II―stapes columella

65

41/24

42.6

(8 - 55)

26.43

(5 - 40)

23.70

(5 - 40)

+2.73

B

Tipo III―major columella

42

20/22

44.8

(16 - 67)

29.16

(15 - 60)

30.01

(15 - 55)

−0.94

C

Type IV―round window

13

8/5

54.7

(20 - 70)

28.81

(20 - 60)

25.20

(20 - 35)

+3.61