American National Standard Qualities and Procedures for Description and Measurement of Environmental Sound – Part 1: Basic Quantities and Definitions
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.