PLASTIC EAR MOLD FOR COMMUNICATIONS EQUIPMENT

Moderate physical blows to an inserted mold produced pain and erythema within the external auditory canal. Because of the rigid structure of the subject device, a more severe or heavier blow might possibly fracture the bony structure of the external auditory canal. The plastic ear mold HS-30 receive...

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Bibliographic Details
Main Author: St John, Joseph H
Format: Report
Language:English
Subjects:
Anatomy and Physiology
COMMUNICATION EQUIPMENT
EAR
EARPHONES
HEARING
HUMAN FACTORS ENGINEERING
Human Factors Engineering & Man Machine System
MOLDINGS
Non-radio Communications
PAIN
PHYSIOLOGY
PLASTICS
SENSES(PHYSIOLOGY)
SHOCK(PATHOLOGY)
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Summary:Moderate physical blows to an inserted mold produced pain and erythema within the external auditory canal. Because of the rigid structure of the subject device, a more severe or heavier blow might possibly fracture the bony structure of the external auditory canal. The plastic ear mold HS-30 receiver headset combination, in which the mold canal is occluded, afforded a partial protection against temporary hearing loss from concussion of gunfire but this protection disappeared when the ear mold was used without the attached HS- 30 receiver headset, in which the mold canal was patent. Temporary hearing loss from field radio communication was less with the plastic ear mold HS-30 receiver headset combination than with the tank headset H16/U. A greater signal to noise ratio of field radio communication was noted with the plastic ear mold HS-30 receiver headset combination than with the tank headset H16/U because a lower volume control setting for adequate reception was required. Moderate manual manipulation of the plastic ear mold or its use in extremes of environmental temperature produced no injury to the ear. Pub in Medical Department Field Research Lab., Project No. 57-5. 30 Sep 1947.