IS NIHL (NOISE INDUCED HEARING LOSS) A COMMON PROBLEM AT WORK?
NIHL has been studied extensively in the military and industry. Federal regulations require hearing conservation programs for industry. Smaller employers and agriculture are exempt from these requirements. Research on exposure to agricultural noise sources is more important than ever. The role of agricultural noise in NIHL is not new; the University of Nebraska has been studying tractor noise since 1970. HOW DOES NIHL OCCUR? NIHL occurs in several ways. The first stage is a temporary threshold shift in the pattern of hearing. The shift raises the level of loudness required to hear sounds and is accompanied by tinnitus (ringing or buzzing in the ears) and a mild hearing loss at the higher frequencies. Hearing returns to normal within a few hours or one – two days after the ear has had time to rest. A permanent threshold shift in the pattern of hearing may occur after repeated temporary threshold shifts, or it may occur after a single acute exposure of high intensity such as having a gun
