RELATIVE HEARING LEVELS AND TYPES OF HEARING LOSS AMONG FOUR SELECTED GROUPS OF AIR FORCE PERSONNEL

摘要

The relative hearing levels of right and left ears were investigated in four selected groups of Air Force personnel. One group consisted of 25 non-noise-exposed Class A men (designated Ann);the other three groups were made up of noise-exposed individuals, specifically, 25 Class A, 50 Class B (re AFR 160-3, 1956), and 25 Class C (average of more than 15 db). Pure-tone air-conduction and bone-conduction audiometric tests were administered with a Beltane Model 15A audiometer with Telephones TD1I-39 earphones. Air-conduction thresholds were established for each subject at the following frequencies:250, 500, 1000, 1500, 2000, 3000, 4000, and 6000 cps. Bone-conduction thresholds were measured at 250, 500, 1000, 2000, and 4000 cps. Each subject was interviewed, and a comprehensive history questionnaire was completed for him. Data on each subject's awareness of a preferred or better car were also obtained.