Effects of earplugs and protective headgear on auditory localization ability in the horizontal plane
Journal/Book: Hum Factors. 1999; 41: Box 1369, Santa Monica, CA 90406, USA. Human Factors Soc. 282-294.
Abstract: The purpose of this study was to determine how well humans localize sound sources in the horizontal plane while wearing protective headgear with and without hearing protection. In a source identification task, a stimulus was presented from 1 of 20 loudspeakers arrayed in a semicircular are, and participants stated which loudspeaker emitted the sound. Each participant was tested in 8 conditions involving various combinations of wearing a Kevlar(R) army helmet and two types of earplugs. Testing was conducted at each of 2 orientations (frontal and lateral). In the frontal orientation, overall error was slightly greater in all protected conditions than in the bare-head control condition. In the lateral orientation, overall error score in the protected conditions was substantially and significantly greater than in the bare-head control conditions. Most errors in the lateral orientation were accounted for by front-back confusions, indicating that the protective devices disrupted high-frequency spectral cues that are the basis for discriminating front from back sound sources. The results have practical implications for the use of protective headgear and earplugs in industrial or military environments where localization of critical sounds is important.
Note: Article Grantham DW, Vanderbilt Bill Wilkerson Ctr Otolaryngol & Commu, 1114 19th Ave S, Nashville,TN 37212 USA
Keyword(s): SOUND LOCALIZATION; HEARING CONDITIONS; TOPOGRAPHY; ACUITY; SPACE; CUES