Abstract :
The unusual conditions imposed by flight on the sense of hearing are stated, showing the need of audiometric study. After brief review of the theory of the audiometer, data are submitted covering: (a) fatigue as indicated by measurements before and after flight, (b) fatigue as vndicated by measurements taken during flight, (c) initial impairment coincident with flight, (d) group measurements of fliers and non-fliers as a test for permanent impairment. The results are discussed with particular view to their bearing on aircraft radio operation.
