Noise Levels on Aircraft Carrier Flight Decks and Their Effects on Humans

Measurements were made of noise levels produced by four aircraft during pilot qualification exercises aboard the flight deck of USS KITTY HAWK. These measurements, on both the A- and C-weighting networks, were augmented by calculations of speech-interference levels made later from tape recordings. These data were compared to similar measurements made at the Naval Air Test Center at Pautuxent River, Maryland, and interpreted in terms of deafness risk and interference with speech communications. The levels measured on the carrier showed large amounts of low-frequency energy (at octaves centered at 62 and 125 Hz) not present in the data taken ashore; this variation is ascribed to the presence of blast deflectors on the carrier and to the effects of strong wind across the deck and the measuring microphone in its wind screen. The noise levels measured are shown to severely degrade speech communications and to present a risk of deafness to personnel. Measure the noise levels produced by aircraft landing on and taking off from flight decks of aircraft carriers. Assess these levels in terms of (1) the hearing hazards they present to personnel exposed to them for various periods of time, with varying degrees of ear protection, and (2) the extent to which they degrade speech communication. When noise exposures were extrapolated to a 12-h cyclic air operation, hearing hazards were predicted, even when current ear-protection devices were utilized. Direct observation together with calculation of speech-interference levels indicated significant decrement in voice communication under high-noise conditions.