Effectiveness of foam earplug hearing protection for artillerymen firing L118/119 105 mm howitzers

A field study was carried out to study the effect of firing the British L118/9 195 mm howitzer (Hamel gun) on the hearing of crewmen wearing EAR earplugs. Two guns and gun crews were placed 7 m apart, each gun firing 40 rounds during each of 2 successive days. Bekesy type audiometry was carried out before and after firing and was also used to measure the attenuation or goodness of fit of the earplugs. No significant hearing loss was measured in any of the crewmen. It was concluded that, if correctly fitted, EAR earplugs provide adequate hearing protection under these exposure conditions.