title: Measurement of impulse peak insertion loss from two acoustic test fixtures and four hearing protector conditions with an acoustic shock tube.
abstract: Impulse peak insertion loss (IPIL) was studied with two acoustic test fixtures and four hearing protector conditions at the E-A-RCAL Laboratory. IPIL is the difference between the maximum estimated pressure for the open-ear condition and the maximum pressure measured when a hearing protector is placed on an acoustic test fixture (ATF). Two models of an ATF manufactured by the French-German Research Institute of Saint-Louis (ISL) were evaluated with high-level acoustic impulses created by an acoustic shock tube at levels of 134 decibels (dB), 150 dB, and 168 dB. The fixtures were identical except that the E-A-RCAL ISL fixture had ear canals that were 3 mm longer than the National Institute for Occupational Safety and Health (NIOSH) ISL fixture. Four hearing protection conditions were tested: Combat Arms earplug with the valve open, ETYPlugs ® earplug, TacticalPro headset, and a dual-protector ETYPlugs earplug with TacticalPro earmuff. The IPILs measured for the E-A-RCAL fixture were 1.4 dB greater than the National Institute for Occupational Safety and Health (NIOSH) ISL ATF. For the E-A-RCAL ISL ATF, the left ear IPIL was 2.0 dB greater than the right ear IPIL. For the NIOSH ATF, the right ear IPIL was 0.3 dB greater than the left ear IPIL.
authors.affiliation: Division of Applied Research and Technology, National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Murphy
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: Fackler
authors.forename: Elliott H
authors.initials: EH
authors.lastname: Berger
authors.forename: Peter B
authors.initials: PB
authors.lastname: Shaw
authors.forename: Mike
authors.initials: M
authors.lastname: Stergar
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D001309:Auditory Threshold; D004430:Ear Protective Devices / Q000592:standards*; D006317:Hearing Loss, Noise-Induced / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D006320:Hearing Tests / Q000379:methods; D006801:Humans; D009623:Noise, Occupational / Q000009:adverse effects / Q000517:prevention & control; D015203:Reproducibility of Results; D014481:United States; D014484:United States Environmental Protection Agency