the current occupational safety and health administration definition of a `` '' change in hearing threshold relative to the baseline audiogram of an average of 10 db or more at 2 , 3 or 4 khz in either ear '' '' and the american academy of otolaryngology-head and neck surgery recommendation of a `` '' 10 db or greater change for the worse for either the 0.5 , 1 , 2 khz pure tone average or the 3 , 4 , 6 khz pure tone average , in either ear '' '' were supported .
C0018670
y-he
C0013443
er