Acoustics - Hearing protectors - Part 2: Estimation of effective A-weighted sound pressure levels when hearing protectors are worn (ISO 4869-2:1994); German version EN ISO 4869-2:1995, Corrigenda to DIN EN ISO 4869-2:1995-08; German version EN ISO 4869-2:1995/AC:2007— 2 стр.
Acoustics; hearing protectors; part 3: simplified method for the measurement of insertion loss of ear-muff type protectors for quality inspection purposes (ISO/TR 4869-3:1989); German version EN 24869-3:1993— 10 стр.