Comparison of different types of hearing protection devices for use during weapons firing

Abstract: Introduction: Hearing protection devices (HPDs) are not rated for impulse noise, which makes it difficult to select an appropriate device for use during weapons firing. Measurements of different types of HPDs (level independent, level dependent, earplugs, and earmuffs) were performed following American National Standards Institute/Acoustical Society of America S12.42 procedures. Methods: A rifle producing a peak level of 154 decibels of sound pressure level was used as the noise source for the measurements. The devices tested were E-A-R Classic earplugs, Combat Arms double-end earplugs, ETY·Plugs earplugs (standard fit), Peltor H10A earmuffs, and Peltor PowerCom Plus earmuffs. The earmuffs were also tested in combination with the E-A-R Classic earplugs and with ballistic glasses. Results: The earplug and earmuff combinations provided the most protection, followed by the level-independent earplugs, earmuffs, and level-dependent earplugs. Wearing of ballistic glasses reduced the effectiveness of the earmuffs. Discussion: Although the results provide information about the level of protection that is possible for several types of HPDs, the best choice of HPD depends on the operational setting. The combination of level-independent earmuffs and earplugs was the most effective, but it is not a practical solution when communication is required. Earplugs should be worn in cases in which earmuffs interfere with sighting the weapon or are incompatible with other gear such as a helmet or glasses. Future work should include different types of communication headsets and different combinations of HPDs.