本文件规定了三种方法（倍频程法、HML法和SNR法）来估计佩戴护耳器时有效的A计权声压级。该方法适用于噪声的声压级或等效连续声压级。虽然这些方法主要用于稳态噪声暴露，但也适用于含有脉冲成分的噪声。这些方法可能不适合用于峰值声压级测量。倍频程、H、M、L或SNR值适用于确定选择或比较听力保护器的声衰减标准，和\/或设置可接受的最低声衰减要求。

This document specifies three methods (the octave-band, HML and SNR methods) of estimating the A-weighted sound pressure levels effective when hearing protectors are worn. The methods are applicable to either the sound pressure level or the equivalent continuous sound pressure level of the noise. Although primarily intended for steady noise exposures, the methods are also applicable to noises containing impulsive components. It is possible that these methods could not be suitable for use with peak sound pressure level measurements. The octave-band, H, M, L or SNR values are suitable for establishing sound attenuation criteria for selecting or comparing hearing protectors, and/or setting minimum acceptable sound attenuation requirements.