本美国国家标准规定了一种通过比较混响环境中原位安装的噪声源（机械或设备）发出的测量声压级与校准参考声源发出的声压级来确定噪声源声功率级或声能级的方法。声级或噪声发射的瞬时频率或倍频程（在一种情况下，噪声发射的功率或倍频程）。使用倍频程计算声功率级或声能级以及应用的频率A- 波段级别。

This American National Standard specifies a method for determining the sound power level or sound energy level of a noise source by comparing measured sound pressure levels emitted by a noise source (machinery or equipment) mounted in situ in a reverberant environment, with those from a calibrated reference sound source. The sound power level (or, in the case of noise bursts or transient noise emission, the sound energy level) produced by the noise source, in frequency bands of width one octave, is calculated using those measurements. The sound power level or sound energy level with frequency Aweighting applied is calculated using the octave-band levels.