本标准提供了在各种气象条件下计算任何声源（移动或静止声源）的大气吸收损失的方法。假设大气是静止的、均匀的、成分正常的潮湿空气。非均匀大气可分为水平层，在水平层内可假设均匀条件。纯音的衰减系数是通过方程（或表格）在频率范围内，以及大气的湿度、压力和温度来计算的。对于通过分数倍频程滤波器（例如，三分之一倍频程滤波器）分析的声音，附录中提供了替代方法，以计算大气吸收引起的衰减，而不是纯音声音的衰减。

This Standard provides the means to calculate atmospheric absorption losses of sound from any source, moving or stationary, for a wide range of meteorological conditions. The atmosphere is assumed to be still, homogeneous moist air of normal composition. Non-homogeneous atmospheres can be divided into horizontal layers within which homogeneous conditions can be assumed. Attenuation coefficients for puretone sounds are calculated by means of equations (or a table) over ranges of frequency, and the humidity, pressure, and temperature of the atmosphere. For sounds analyzed by fractional-octave-band filters (e.g., one-third-octave-band filters), alternative methods are provided in annexes to calculate the attenuation caused by atmospheric absorption from that specified for pure-tone sounds.