Document ZgX8m7jDNNpvLYb4qKvaK1mY

40--Noise and Hearing Conservation INCIDENCE OF HEARING IMPAIRMENT IN PERCENT OF POPULATIONS- General Population and Non-Noise 90 100 A-Scale Level in db 110 Fic 40-6 --Incidence of hearing impairment in the general population and in selected populations by age groups and by occupational noise exposure Hearing impairment may be defined as the average hearing threshold level in excess of 15 dB at 500, 1000, and 2000 Hz From American Industrial Hygiene Association Journal, October 1967 1250