Aircraft noise effects on sleep: DLR research results and their application

DLR studied human reactions to nocturnal aircraft noise in laboratory and field experiments for developing sound criteria for the protection of residents living near airports. The results of the field studies were utilized by the Regional Council of Leipzig for establishing a noise protection plan during night in the official approval process of the expansion of airport Leipzig/Halle. In the laboratory, 128 subjects were examined during 13 consecutive nights, including 16 control subjects. 4 to 128 aircraft noise events (ANEs) were applied per night with maximum sound pressure levels (SPLs) between 45 and 80 dB(A). Sleep was assessed by polysomnography. Electrophysiological signals were simultaneously recorded with ANEs for analyzing event-related reactions. Data and results were validated in the field with 64 residents during 9 consecutive nights living near Cologne airport. In the laboratory, aircraft noise led to some sleep fragmentation, as stage 1 and awakenings were significantly increased, and slow wave sleep reduced compared to baseline nights. Dose-response relationships were established regarding number and maximum SPL of ANEs. In the field, aircraft noise hardly changed sleep structure. At the same maximum SPL, awakening probability was much lower, but habituation was not complete. Based on the field results, new criteria for protecting residents against nocturnal aircraft noise were developed and exemplified for the extension of airport Leipzig/Halle. The aims of the protection plan are: (1) on average, less than one additional awakening should be induced by aircraft noise, (2) awakenings recalled in the morning should be avoided as much as possible, (3) aircraft noise should interfere with the process of falling asleep again as little as possible