Effects of nocturnal aircraft noise- Overview of the DLR human specific investigations

497] OBJECTIVES Studies on the effects of aircraft noise on sleep with a large subject sample as well as with high methodological expense are lacking, and hence statistically reliable recommendations for the protection against aircraft noise can presently not be made. However, scientifically based investigations are necessary for providing proper guidelines for authorities and users. METHODS DLR studied human reactions to nocturnal aircraft noise in laboratory and field experiments: In total, 192 healthy volunteers (m/f), aged 18 to 65 years, underwent 2240 study nights. In the isolation facility of the institute, 128 subjects were examined during 13 consecutive nights. 16 subjects served as control. For 112 subjects, aircraft noise events have been applied between 4 and 128 times per night (45 ≤ LAS,max ≤ 80 dB(A)). Sleep disturbances were assessed by EEG, EOG, EMG and EKG, by respiration, finger-pulse amplitude and position in bed. These signals were simultaneously recorded with the acoustic signals for calculating event-correlated reactions. The concentrations of cortisol, adrenalin and noradrenalin were determined from all night urine samples. At evening and morning, performance tests and questionnaires (fatigue, mood, annoyance) were applied. These data and results were examined in two field studies with 64 volunteers during 9 consecutive nights at their homes near Cologne airport. CONCLUSIONS The investigations will be concluded in March 2004. They are very ambitious and unique, even on a world wide standard. DLR wants to contribute by profound experimental knowledge to the very controversial disputes about the degree of impairing effects on human specific reactions to nocturnal aircraft noise.