EN 24869-1:1992

Committees responsible
National foreword
Method
1. Scope
2. Normative references
3. Definitions
4. Measurement of the sound attenuation of hearing
     protectors
Annexes
A. Uncertainty of sound attenuation measurements
B. Bibliography
Tables
1. Allowable field variation for different microphones
2. Maximum permissible background sound pressure level
3. Minimum and maximum sound pressure levels for test
     signals
A.1 Repeatability and reproducibility of sound
     attenuation measurements on ear-muffs at a
     probability level of 95% (according to ISO 5725)
A.2 Repeatability and reproducibility of sound
     attenuation measurements on ear-plugs at a
     probability level of 95% (according to ISO 5725)

Specifies a method for measuring sound attenuation at the threshold of hearing. The procedure is designed to yield values close to the maximum attenuation which are not normally attained under field conditions. The values reflect the attenuating characteristics only to the extent that users wear the device in the same manner as did the test subjects. Data are collected at low sound pressure levels but which are also representative of the values at higher sound pressure levels.