This standard is an adaptation of the International Standard ISO 1999:1990(E) of the same name. Unlike the international standard, This standard allows assessment of noise exposure using a time/intensity trading relation other than a 3-decibel increase per halving of exposure time. This standard presents, in statistical terms, the relationship between noise exposures and changes in hearing threshold levels for a noise-exposed population. This standard can also be applied to the calculation of the risk of incurring hearing handicap from sustained daily exposure to noise. Guidance is provided as to the measurement of noise exposure.