Effects of nocturnal rail traffic noise on sleep - Methodology and study design

Kurzfassung

One concept of European common transport policy is to shift more and more freight traffic to railway. Prognoses assume growth rates up to 20% on some tracks until 2015. In particular Germany is the main transit country for north-south and east–west traffic in Europe and thus people living near the railway tracks are more and more affected by this increasing railway noise. Within a German-French cooperation on traffic research (DeuFrako), mainly funded by the German ministry of economics and the French ministry of transport, in spring 2008 the DLR-Institute of Aerospace Medicine started a 15-month field study examining the effects of nocturnal rail traffic noise on sleep (part of the sub-project RAPS (Railway noise, Annoyance, Performance, Sleep)). In this study altogether 32 subjects are polysomnographically investigated during 9 consecutive nights each. Electrophysiological signals include EEG, EOG, EMG, ECG, respiratory movements and finger pulse amplitude. Three sound level meters (class 1) continuously measure the sound pressure level LAS and LAF two metres in front of the facade and at the sleeper’s ear for every night. In addition, every time the external background level L90 is exceeded by 3 dB, both the external as well as the internal noise is recorded. In this presentation, methodology and the design of this field study is presented.