Noise Attenuation of Hearing Protectors in the Human Ear – A Method Description

A method was developed with which noise attenuation can be measured between the ear drum and an ear plug with the aid of a microphone. This objective measurement method gave reliable results when compared with the results of laboratory measurements. For selected ears the pink noise attenuation, as the A-weighted level, was 28–31 dB for the ear plugs and 41 dB for the combination of car plugs (Ear Classic) and ear muffs (Peltor H61). In addition, in this study, impulse noise attenuation was measured; it ranged from 29 to 31 dB for ear plugs and was 46 dB for the combined use of ear plugs (Ear Classic) and ear muffs (Peltor H61). Pink noise attenuation, as the A-weighted value and the C-weighted peak level, against assault rifle shots gave very similar attenuation values at the decibel level. The standard deviation values were 7–9 dB for the ear plugs, 1–3 dB for the ear muffs and 7–8 dB for the combined use of plugs and muffs. The developed method is reliable and offers new possibilities for measuring the attenuation of hearing protectors in field conditions.