Environmental awareness and level-dependent hearing protection devices.
OBJECTIVE
The effect of level-dependent hearing protection devices (HPDs) on subjects' ability to identify real-life environmental sounds was investigated.


METHODS
Eighteen subjects with no hunting experience attempted to identify sounds (crow, duck, turkey, deer, owl, goose, and person) recorded at various distances in the presence of the SoundScope and Sonic II level-dependent HPDs as well as in an open ear condition. Knowles Electronic's Manikin for Auditory Research was employed in making the experimental recordings. The Sonic II accomplishes level-dependent attenuation via a passive mechanism, whereas the SoundScope employs active circuitry that attenuates loud sounds while providing a small amount of high frequency amplification for soft sounds. Both devices are commercially available and are advertised for hunters/shooters. Sound identification scores (SISs) were determined for each condition.


RESULTS
Mean SISs differed significantly among the three earplug conditions, collapsed over type of sound and distance, with the best SIS obtained under the open ear condition (96.43%) and the worst under the Sonic II condition (84.13%). Further analysis revealed that the listening conditions differed significantly only at the 100 yard distance.


CONCLUSIONS
Auditory awareness was not maintained by either device investigated during the 100 yard condition. However, auditory awareness was maintained by both devices at a distance of 75 yards or closer. These devices may be appropriate for use in certain hunting/shooting situations depending on several factors including type of game being hunted, environment, and shooting range of the weapon. Further support also is provided for the usage of level-dependent HPDs during recreational shooting activities (i.e., at a shooting range).
Lindley
G A
GA
University of Pittsburgh, Pennsylvania, USA.
Palmer
C V
CV
Goldstein
H
H
Pratt
S
S
D000293:Adolescent; D000328:Adult; D001301:Audiometry, Pure-Tone; D001307:Auditory Perception; D001364:Awareness; D004430:Ear Protective Devices; D004777:Environment; D005260:Female; D006801:Humans; D008297:Male