PURPOSE. This NPG establishes minimum requirements for an Agencywide Hearing Conservation Program and is intended to prevent noise-induced hearing loss. Occupational exposure to noise has been shown to be a contributing factor in the development of noise-induced hearing loss. Loss of hearing can result from exposure to impulse or impact noise, as well as from exposure to steady-state (continuous/intermittent) noise. The hearing loss may be temporary or may become permanent through repeated exposure of unprotected personnel to hazardous noise. Initial deterioration of hearing may not be apparent to the individual. By the time there is subjective awareness of the loss, the impairment may be substantial and irreversible. Hearing loss due to noise exposure is almost entirely preventable. Therefore, concerted preventive efforts are warranted to ensure that the hearing of employees is conserved.

APPLICABILITY. This NPG is applicable to NASA Headquarters and NASA Centers, including Component Facilities, and to JPL to the extent specified in its contract and includes all ground-based and aircraft operations, all aircraft pilots, and crew members. This document does not apply to space and space flight operations. A separate document entitled "NASA Flight Crew Hearing Conservation Program" (JSC-28927) governs this. While, referencing the NASA Occupational Hearing Conservation Program, the noise limits imposed are lower than those for ground operations because space operations must protect not only against the direct otologic effects of noise, but also against its impact on performance including impaired concentration, stress, agitation, and sleep disturbances.