Manifestations

Grade III, Level A (n = 140/100%)

Grade II, Level A (n = 110/100%)

χ²

p-value

Drumming

36/25.71%

0/0.00%

33.04

<0.01

Distending pain in the ears

36/25.71%

0/0.00%

33.04

<0.01

Otalgia

30/21.43%

0/0.00%

26.79

<0.01

Relief of symptoms (if any) after work

93/66.43%

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