A comparison of the effects of night time air traffic noise on sleep at Cologne/Bonn and Frankfurt Airport after the night flight ban

In the STRAIN study (2001/2002) the German Aerospace Center (DLR) measured the sleep of 64 residents (19-61 years old, average: 38 years) around Cologne/Bonn airport for 9 consecutive nights each with polysomnography. Cologne/Bonn airport has no night time restrictions for chapter 3 airplanes and is one of the busiest airports in Germany during the night. Frankfurt is the airport with the highest traffic volume in Germany. A night flight ban (11 p.m. - 5 a.m.) was implemented in October 2011. Traffic density during shoulder hours is high. DLR examined 83 Frankfurt airport residents (18-77 years old, average: 43 years) with polysomnography as part of the NORAH study in 2012. In both studies sound pressure level and noise events were recorded with microphones near the sleeper's ear. Participants filled out questionnaires each morning. The analysis shows that aircraft noise induced awakening probabilities are 3.8-7.5% higher for maximum indoor levels from 30-70 dB(A) at Cologne/Bonn Airport whereas night time aircraft noise annoyance is considerably increased in Frankfurt. The results of both studies are compared, and limitations of the comparisons are discussed.