Location comparison: every airport is different
A central element of the Quality of Life Study is the comparison of four airports in Germany. The scientists wanted to find out whether people living near Frankfurt, Cologne/Bonn und Stuttgart airports and around the planned Berlin-Brandenburg airport felt equally annoyed at similar noise levels. The four airports differ in several respects:
- In Frankfurt there has been a curfew on scheduled take-offs and landings between 23:00 and 05:00 hrs since October 2011. In addition to this, the noise background changed in the same month because a new runway went into operation. This is why a change effect was expected here.
- There are no flight movements as yet at Berlin-Brandenburg airport – at the time of the survey the only air traffic noise in the region came from Berlin's Schönefeld airport. But when the airport is opened there will be a change in the noise background in the region. This could lead to a change effect.
- In Cologne/Bonn there are also take-offs and landings at night. There are no plans for expansion.
- In Stuttgart there are no flights at night and, as in Cologne/Bonn, there are no plans for expansion.
The NORAH team asked several thousand people in the environs of the four airports how annoyed they felt on a five-point scale by the air traffic noise over the previous twelve months, and how they assessed their own quality of life and sleep quality. 1 stood for "absolutely no annoyance" and 5 for "extremely high annoyance". Acoustic experts also calculated the continuous sound level for the specific addresses of the study participants.
Where do most of the "highly annoyed" persons live?
As already shown in the time comparison in the Rhine-Main region, the proportion of "highly annoyed" persons also played an important role in the location comparison. All participants who evaluated their noise-related annoyance with either 4 or 5 are regarded by the scientists as "highly annoyed".
In this way the NORAH team found out that the people at the different locations felt annoyed to very different degrees: more people in Cologne/Bonn feel annoyed by continuous sound levels up to about 52 decibels than in Stuttgart and Berlin-Brandenburg. With increasing loudness, the proportion of "highly annoyed" persons rises in Stuttgart. The proportion of "highly annoyed" persons is even higher in the environs of Frankfurt airport: as of a sound level of around 45 decibels, more people in the Rhine-Main region in 2013 felt highly or extremely annoyed than at the other airports. In 2011 there were more "highly annoyed" persons in Frankfurt at sound levels over 47 decibels than in Cologne/Bonn. In 2012 the annoyance in Frankfurt was especially high compared with the other three locations – probably due to the change effect. Even at a continuous sound level from around 42 decibels, considerably more people in the region felt "highly annoyed" by air traffic noise than at the other three locations. However, at all four investigated airports the noise-related annoyance is higher than would be expected on the basis of the standard graphs used in the European Union to calculate air traffic noise-related annoyance.
How residents around airports assess their sleep quality
A somewhat different picture emerged when the scientists analyzed the answers on sleep quality at the various locations. Within the framework of the Quality of Life Study, the NORAH team did not directly examine the sleep quality of the study participants, but rather asked them to what extent their sleep was disturbed by traffic noise. A five-point scale was again used here. The result: in 2011, i.e. before the introduction of the curfew on scheduled flights between 23:00 and 05:00 hrs at Frankfurt airport, the people in this region felt considerably more disturbed in their sleep by air traffic noise than those at other airports - at both low and high continuous sound levels. In the two following years, the sleep disturbances decreased somewhat from the point of few of the people concerned in the Frankfurt region: at continuous sound levels from around 57 decibels, the people here perceived their sleep as less disturbed than the respondents in the environs of the planned Berlin-Brandenburg airport. At lower continuous sound levels the people in the Rhine-Main region still felt more disturbed in their sleep. This is followed in second place by the respondents in the environs of Cologne/Bonn airport. A further analysis of the answers showed that the respondents were mainly of the opinion that they slept better through the night after the introduction of the night flight curfew at Frankfurt airport. Their assessments of the sleep onset and REM sleep phases differ substantially less from each other in the three years. For further results on the sleep quality in the Rhine-Main region, please refer to the NORAH Sleep Study (see NORAH Knowledge No. 10 – results of the Sleep Study).