Enhanced awakening probability of repetitive impulse sounds

Abstract

In the present study relations between the level of impulse sounds and the observed proportion of behaviorally confirmed awakening reactions were determined. The sounds (shooting sounds, bangs produced by door slamming or by container transshipment, aircraft landings) were presented by means of loudspeakers in the bedrooms of 50 volunteers. The fragments for the impulse sounds consisted of single or multiple events. The sounds were presented during a 6-h period that started 75 min after the subjects wanted to sleep. In order to take account of habituation, each subject participated during 18 nights. At equal indoor A-weighted sound exposure levels, the proportion of awakening for the single impulse sounds was equal to that for the aircraft sounds. The proportion of awakening induced by the multiple impulse sounds, however, was significantly higher. For obtaining the same rate of awakening, the sound level of each of the successive impulses in a fragment had to be about 15-25 dB lower than the level of one single impulse. This level difference was largely independent of the degree of habituation. Various explanations for the enhanced awakening probability are discussed.

ICBEN review of research on the biological effects of noise 2011-2014

“…A few studies dealing with more “special” noise sources and their impact on sleep have also appeared in recent years, such as the work of Vos and Houben, who presented a re-analysis of data gathered from a study that investigated signalled awakening effects from shooting and civil impulse sounds[ 177 ] and found that multiple impulse sounds (e.g., shooting sounds appearing in a volley) induced higher awakening rates at the same overall sound exposure level than did single impulse sounds such as aircraft landings. A Swiss field study investigated 27 subjects living in the vicinity of churches that ring bells during the night, using polysomnography, and extrapolated the awakening effect to a larger population in the greater Zurich area.…”