An investigation of differences in startle physiological measures between sonic booms and other transients

摘要

In previous research on response to high-level sonic booms, startle has been identified as an issue and in a recent study on low-level sonic booms, it was also found that people’s evaluations of startle correlated strongly with their evaluations of annoyance. That research is based on subjective judgments rather than physiological measurements to evaluate startle. An experiment is described that was set up to examine the startle reflex when subjects are exposed to low-amplitude sonic booms and the relationship between the physical reactions and the subjective evaluations of startle. The startle reflex is often characterized by involuntary muscle activity and an increase in central nervous system activity caused by exposure to sudden, impulsive sounds. There have been many physiological measures that have been shown to correlate to startle such as electromyography of the eye-lid or neck muscles, skin conductance between the fingers, and heart rate acceleration. However, most psycho-physiological research conducted on startle has been limited to using simplistic sound stimuli (such as white noise pulses or tones) to evoke startle responses. Therefore it is unknown how much of this previous research could be applied to evaluating startle evoked by supersonic aircraft noise. A pilot experiment was conducted to investigate how physiological measures of startle vary with different impulsive stimulus types including low-amplitude sonic booms. Reported here are preliminary results of that experiment.