ASA S12.9 Part 1 PDF download

ASA S12.9 Part 1 – American National Standard Qualities and Procedures for Description and Measurement of Environmental Sound – Part 1: Basic Quantities and Definitions

This standard describes basic quantities and general procedures for assessment of sound withrespect to community response. Research on the ways in which people and communities are affectedby common everyday noises in the environment has led to a variety of measures for assessment ofdifferent types of noise. The variety of measures has introduced some confusion about the relationshipamong the measures and their applicability for specific purposes. This standard defines consistentmeasures 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 communitysound except high-energy impulsive sound. A C-weighted sound exposure level is used to describehigh-energy impulsive sounds such as blasts or sonic boom, and it may be used to describe other lowfrequencysound sources such as industrial processes, transportation sources and electric powergenerating facilities. The Annex provides information concerning some of the basic quantities thathave been used to describe certain environmental sounds.