title: Effects of Active and Passive Hearing Protection Devices on Sound Source Localization, Speech Recognition, and Tone Detection.
abstract: Hearing protection devices (HPDs) such as earplugs offer to mitigate noise exposure and reduce the incidence of hearing loss among persons frequently exposed to intense sound. However, distortions of spatial acoustic information and reduced audibility of low-intensity sounds caused by many existing HPDs can make their use untenable in high-risk (e.g., military or law enforcement) environments where auditory situational awareness is imperative. Here we assessed (1) sound source localization accuracy using a head-turning paradigm, (2) speech-in-noise recognition using a modified version of the QuickSIN test, and (3) tone detection thresholds using a two-alternative forced-choice task. Subjects were 10 young normal-hearing males. Four different HPDs were tested (two active, two passive), including two new and previously untested devices. Relative to unoccluded (control) performance, all tested HPDs significantly degraded performance across tasks, although one active HPD slightly improved high-frequency tone detection thresholds and did not degrade speech recognition. Behavioral data were examined with respect to head-related transfer functions measured using a binaural manikin with and without tested HPDs in place. Data reinforce previous reports that HPDs significantly compromise a variety of auditory perceptual facilities, particularly sound localization due to distortions of high-frequency spectral cues that are important for the avoidance of front-back confusions.
authors: Department of Physiology & Biophysics, University of Colorado School of Medicine, Aurora, Colorado, United States of America.
authors: Andrew D
authors: AD
authors: Brown
authors: Department of Speech, Language, and Hearing Sciences, University of Colorado-Boulder, Boulder, Colorado, United States of America.
authors: Brianne T
authors: BT
authors: Beemer
authors: Department of Physiology & Biophysics, University of Colorado School of Medicine, Aurora, Colorado, United States of America.
authors: Nathaniel T
authors: NT
authors: Greene
authors: Applied Research Associates, Inc., Littleton, Colorado, United States of America.
authors: Theodore
authors: T
authors: Argo
authors: Applied Research Associates, Inc., Littleton, Colorado, United States of America.
authors: G Douglas
authors: GD
authors: Meegan
authors: Department of Physiology & Biophysics, University of Colorado School of Medicine, Aurora, Colorado, United States of America.
authors: Daniel J
authors: DJ
authors: Tollin
mesh_terms: D000328:Adult; D004430:Ear Protective Devices; D006801:Humans; D008297:Male; D010898:Pitch Perception; D013017:Sound Localization; D013067:Speech Perception