The attenuation of hearing protectors against high-level shooting impulses

The acoustical attenuation of five different hearing
protectors were investigated using real impulses and miniature microphone
technique in field conditions from a 23 mm antiaircraft cannon, from 122 mm
howitzer and from an explosion of 1 kg of TNT. The measurements were carried out
using voluntary military officers exposed to similar impulses in their work. The
combination of earmuffs and earplugs proved to give the best attenuation. The
attenuation of the earmuffs was related to the size of the cup. Light protectors
gave practically no protection against the highest impulses from howitzer and
TNT-blasts.