This standard describes basic quantities and general procedures for assessment of sound with respect to community response. Research on the ways in which people and communities are affected by common everyday noises in the environment has led to a variety of measures for assessment of different types of noise. The variety of measures has introduced some confusion about the relationship among the measures and their applicability for specific purposes. This standard defines consistent measures for physical quantities that may be used to measure and assess environmental sound.

Time-average A-weighted sound level is adopted in this standard as a basic quantity for all community sound except high-energy impulsive sound. A C-weighted sound exposure level is used to describe high-energy impulsive sounds such as blasts or sonic boom, and it may be used to describe other lowfrequency sound sources such as industrial processes, transportation sources and electric power generating facilities. The Annex provides information concerning some of the basic quantities that have been used to describe certain environmental sounds.