Loudness of high-intensity aircraft flyovers

Abstract

Casual listening to a recorded aircraft flyover at various peak levels up to 111 dBA gave the impression that reducing the level by 10 dB did not seem to reduce the loudness by half. Therefore a group of eight listeners (lab assistants and students experienced in high-intensity noise exposure) were given pairs of flyovers, the first of which was always at 111-dBA peak and called “100” in loudness, and were asked to indicate the loudness of the second, whose peak level ranged from 61 to 106 dBA. Although the loudness-intensity relation was reasonably close to a power function for each individual, the slopes ranged from 6 to 35 dB per halving loudness, with a median of 16 dB. No listener assigned a loudness of “50” or less to a 101-dBA-peak flyover. Thus, if one wishes to halve the loudness of aircraft noise at the ends of runways, it will be necessary to reduce peak levels by considerably more than the 10 dB that represents an extrapolation from loudness judgments made at moderate levels. The same holds, of course, for “noisiness,” and probably also for “annoyingness.” [Research supported by the National Institute for Occupational Safety and Health, Public Health Service.]