ISO DIS 4869-6

Description / Abstract: This document is concerned with active noise reduction (ANR) earmuffs. It specifies the test methods and calculation procedures for deriving the sound attenuation in active mode. For this aim the values of sound attenuation in the passive mode also have to be known and have to be determined according to ISO 4869-1. These methods are intended for steady noise exposures and are not applicable to noises containing impulsive components.

The test methods of this document are intended to account for the acoustical interaction between the wearer and the device using measurements of passive (REAT, according to ISO 4869-1) and active microphone-in-real-ear (MIRE) measurements as specified in ISO 11904-1.