Sound level measurements of aircraft and vehicle noise, simultaneously recorded at facades and the sleeper´s ear

From 1999-2003 the DLR-Institute of Aerospace Medicine examined the effect of nocturnal aircraft noise on humans sleep. A 15-month field study around Cologne/Bonn-Airport was part of this project. 64 subjects were investigated at 46 different places in 9 consecutive nights in the near neigbourhood of the airport. Three sound level meters (class1) continuously measured the sound pressure level LASmax two metres in front of the facade and at the sleeper’s ear in every night. In addition every time when the external background level L90 was passed by 3 dB, both the external as well as the internal noise was recorded. Altogether more than 16.000 aircraft and nearly 14.000 car noises were recorded. Due to the fact that the main focus of the study was not the determination of facade insulation or room acoustics, but the event related analysis of sleep data and the perceived sound level at the subject’s ear, information about the respective room acoustics, window size or the angles of incident of the noises are not available. However, substantial statements are presented on the differences of the external and internal (at the sleeper’s ear) sound pressure level depending on the window position, on variations during the night and the recording period. Furthermore, examples of frequency spectra variations of the 46 different recording points around the airport are shown