PLASTIC EAR MOLD FOR COMMUNICATIONS EQUIPMENT
Abstract
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1947
- Accession Number
- AD0806399
Entities
People
- Joseph H. St John
Organizations
- United States Army Medical Research Laboratory