title: Azimuthal auditory localization of gunshots in a realistic field environment: effects of open-ear versus hearing protection-enhancement devices (HPEDs), military vehicle noise, and hearing impairment.
abstract: OBJECTIVE
  A controlled field experiment was conducted to evaluate localization of suprathreshold gunshot reports (from blank cartridges) with four hearing protection-enhancement devices (HPEDs) in comparison to the open ear with ambient outdoor noise and in 82 dBA diesel military heavy truck noise.
  
  
  METHODS
  Five measures of localization accuracy and response time for eight shooter positions in azimuth were measured.
  
  
  METHODS
  Nine normal-hearing and four impaired-hearing participants were tested.
  
  
  RESULTS
  Statistical analysis showed worse accuracy and response time performance with the electronic earmuffs (Peltor Com-Tac II™ in full gain position) than with the other tested HPEDs (Etymotic EB 1 and EB 15 High-Fidelity Electronic BlastPLG™ electronic earplugs, both set to Lo gain positions; and 3M Single-Ended Combat Arms™ passive earplug in level-dependent, "open" position). Performance with all HPEDs was worse than that with the open ear, except on right-left confusions, in which the earmuff stood alone as worst, and in response time, for which the EB 1 was equivalent to the open ear. There was no significant main effect of noise on performance. Hearing impairment increased right-left confusions. Subjective ratings related to localization generally corroborated objective localization performance.
  
  
  CONCLUSIONS
  None of the tested HPEDs preserved "normal" localization performance.
authors.affiliation: Auditory Systems Laboratory, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: Kristen A
authors.initials: KA
authors.lastname: Talcott
authors.forename: John G
authors.initials: JG
authors.lastname: Casali
authors.forename: John P
authors.initials: JP
authors.lastname: Keady
authors.forename: Mead C
authors.initials: MC
authors.lastname: Killion
mesh_terms: D000328:Adult; D004430:Ear Protective Devices; D005260:Female; D005389:Firearms; D006309:Hearing; D006317:Hearing Loss, Noise-Induced / Q000517:prevention & control; D006801:Humans; D008297:Male; D008875:Middle Aged; D018986:Motor Vehicles; D009624:Noise, Transportation; D013017:Sound Localization; D055815:Young Adult