title: Better protection from blasts without sacrificing situational awareness.
abstract: A large number of soldiers returning from war report hearing loss and/or tinnitus. Many deployed soldiers decline to wear their hearing protection devices (HPDs) because they feel that earplugs interfere with their ability to detect and localize the enemy and their friends. The detection problem is easily handled in electronic devices with low-noise microphones. The localization problem is not as easy. In this paper, the factors that reduce situational awareness--hearing loss and restricted bandwidth in HPD devices--are discussed in light of available data, followed by a review of the cues to localization. Two electronic blast plug earplugs with 16-kHz bandwidth are described. Both provide subjectively transparent sound with regard to sound quality and localization, i.e., they sound almost as if nothing is in the ears, while protecting the ears from blasts. Finally, two formal experiments are described which investigated localization performance compared to popular existing military HPDs and the open ear. The tested earplugs performed well regarding maintaining situational awareness. Detection-distance and acceptance studies are underway.
authors.affiliation: Etymotic Research, Inc., Elk Grove Village, Illinois, USA. M_Killion@etymotic.com
authors.forename: Mead C
authors.initials: MC
authors.lastname: Killion
authors.forename: Tim
authors.initials: T
authors.lastname: Monroe
authors.forename: Viorel
authors.initials: V
authors.lastname: Drambarean
mesh_terms: D001306:Auditory Pathways / Q000503:physiopathology; D001309:Auditory Threshold; D001364:Awareness; D003463:Cues; D004430:Ear Protective Devices / Q000706:statistics & numerical data*; D004867:Equipment Design; D005107:Explosions; D019416:Head Movements; D015438:Health Behavior; D007722:Health Knowledge, Attitudes, Practice; D006317:Hearing Loss, Noise-Induced / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D006801:Humans; D008887:Military Medicine; D008889:Military Personnel; D009623:Noise, Occupational / Q000009:adverse effects*; D009784:Occupational Diseases / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D009786:Occupational Health Services; D011314:Preventive Health Services; D013017:Sound Localization; D013018:Sound Spectrography; D014481:United States