A laboratory investigation into the effect of quiet-time interval between aircraft noise events on overall noisiness.

In order to investigate the effect of the quiet-time interval between aircraft noise events on the overall negative impression of aircraft noise, psychological experiments were conducted in which the quiet-time interval was varied and the number of events and duration of each stimulus were taken into account. For equal A-weighted equivalent continuous sound pressure level (LAeq) among the stimuli, it was found that overall noisiness decreased as the quiet-time interval ratio of the stimulus was increased. It was also found that the correlation between overall noisiness and LAeq was improved by adjusting for the quiet-time interval ratio or the number of events included in the stimuli, especially when participants paid attention to changes in the instantaneous noise level. This study reveals that LAeq is a good basis for evaluating the negative impressions of aircraft noise, but that correcting for the quiet-time interval and/or number of flights improves the correlation between LAeq and the negative impression in such aircraft noise situations.