The National Institute for Occupational Safety and Health (NIOSH) has organized its research efforts into ten industry sectors. Cross-sector programs are common to many industries. The Hearing Loss Prevention (HLP) Program is a cross-sector program. The Hearing Loss Prevention Program has five strategic research goals. The first four are: surveillance, noise control, hearing protectors and hearing conservation programs. The fifth strategic goal is: Preventing occupational hearing loss through studies of risk factors. Five subgoals have been identified-impulse noise, individual susceptibility, ototoxicity, long term effects of hearing loss and otoprotectants. Impulse noise has been shown to be more damaging to the ear than equal energy continuous noise. NIOSH is currently supporting research to develop metrics for describing impulses and developing hardware to collect impulsive noises. Individual susceptibility has to do with genetic vulnerability to noise. NIOSH is currently conducting a field study of workers looking at nine genetic alleles. Some chemicals in the work environment interact with noise to produce greater hearing loss. NIOSH has partnered with the Nordic Expert Group to document most known ototoxicants. www.nordicexpertgroup.org
Animal work has demonstrated that early-life exposures lead to greater hearing loss later in life than a later-life exposure. NIOSH currently has no project associated with this subgoal. Some chemicals and compounds have been shown in animals to protect the ear from noise. NIOSH currently is interested in the human trials but does not have an active project. The vision of SG 5 is by better understanding the basic mechanisms of hearing loss to reduce the number of OSHA recordable annual hearing losses from 30,000+ in 2004 to less than 22,000 in 2016.