Effect on Directional Hearing in Hunters Using Amplifying (Level Dependent) Hearing Protectors

Abstract

Ear protectors have gained limited use in real hunting situations because they interfere with rifle handling, eye glasses, listening to conversation and environmental sounds, and impair sound localization ability. Level-dependent protectors have relieved some drawbacks, but sound localization is still affected by most protectors. A new, all-in-the-ear protector is promising, and the primary purpose of this study was to investigate influence of all-in-the-ear protectors on sound localization. Experimental laboratory study. Clinical research center. Tertiary referral center. Eleven normal-hearing hunters participated. Realistic sounds were presented from an array of 12 loudspeakers in an anechoic chamber, the sounds being gunshot, breaking twig, human footstep, and dog barking. Four listening conditions were tested: without hearing protection, level-dependent dichotic ear muffs, behind-the-ear protectors, and all-in-the-ear protectors. The unprotected condition gave best sound localization results. All-in-the-ear protectors showed slightly and nonsignificantly poorer results, whereas regular ear muffs and behind-the-ear protectors were significantly poorer in this respect. Gun shot, human footstep, twig breaking, and dog barking showed different results in falling order as regards the possibility to localize the sound source. All-in-the-ear protectors preserve the sound localization ability well in contrast to the other tested protectors, which present confusions particularly around the transversal plane. The sound localization ability is markedly different for the 4 tested realistic sounds.