本文件规定了在听力阈值下测量听力保护器声衰减的主观方法。该方法是一种实验室方法，旨在在受控测量条件下产生可重复的值。这些值仅在使用者以与受试者相同的方式佩戴听力保护器的情况下，才反映听力保护器的衰减特性。 对于现场性能的更具代表性的指示，可以使用ISO/TS 4869-5的方法。 该测试方法产生的数据是在低声压级（接近听力阈值）下收集的，但也代表了较高声压级下听力保护器的衰减值。 如果振幅敏感型听力保护器的声压级高于其电平相关特性生效的点，则会出现例外情况。在这些声压级下，本文件中规定的方法不适用，因为它通常会低估这些设备的声衰减。 注:由于在闭塞耳朵测试中屏蔽了生理噪声，500 Hz以下的声音衰减可能会被高估几分贝。

This document specifies a subjective method for measuring sound attenuation of hearing protectors at the threshold of hearing. The method is a laboratory method designed to yield reproducible values under controlled measurement conditions. The values reflect the attenuating characteristics of the hearing protector only to the extent that users wear the device in the same manner as did the test subjects. For a more representative indication of field performance the methods of ISO/TS 4869？5 can be used. This test method yields data which are collected at low sound pressure levels (close to the threshold of hearing) but which are also representative of the attenuation values of hearing protectors at higher sound pressure levels. An exception occurs in the case of amplitude-sensitive hearing protectors for sound pressure levels above the point at which their level-dependent characteristics become effective. At those sound pressure levels the method specified in this document is inapplicable, as it will usually underestimate sound attenuation for these devices. NOTE Due to masking from physiological noise in the occluded ear tests, sound attenuations below 500 Hz can be overestimated by a few decibels.