Interview with study director Dipl.-Psych. Dirk Schreckenberg: "Integrating the residents to a greater extent"
Dirk Schreckenberg was the director of the Quality of Life Study. In this interview the psychologist talks about the change effect and the practical conclusions that can be drawn from his study. He also tells us whether his work has changed his own reaction to noise.
NORAH Knowledge: Your study shows that the continuous sound level – i.e. the average level and quantity of noise – can only partially explain how severely annoyed people feel. Does that mean that people are exaggerating their degree of annoyance?
Dirk Schreckenberg: Definitely not. In our surveys the people are not asked to guess how many decibels they are hearing. They simply say if what they hear causes them annoyance. This means that they assess their own situation: the noise itself, i.e. how loud and how long the noises are in their perception, how often they occur. But the time of day also plays a role, as well as whatever they happen to be doing at that time. If I am mowing the lawn in the afternoon, the sound of a plane will bother me less than on a summer evening when I'm sitting with friends on the patio. All of this goes into the answers.
The "human factor" becomes particularly apparent in the so-called change effect. Why is it that a whole region will feel more annoyed when an airport expansion is imminent?
Science can only speculate on that at the moment. What we do know is that this is not a one-off phenomenon that only occurs in Frankfurt or only for air traffic noise. There are also studies that have observed a change effect in relation to road traffic noise. One possible explanation is that people always react more strongly to changes than to something that is constantly there. When a noise situation changes, the people notice it and are especially attentive. And that is then reflected in their assessment of the annoyance. Another possible explanation is that non-acoustic factors can also have an influence on how strongly someone feels annoyed. This includes their attitude towards the noise source, i.e. whether, for example, they generally regard aviation or cars as useful. And the attitude towards the responsible institutions also plays a role: whether regional politicians, the airlines, or the local authorities are taking the living situation of the people seriously and protecting them from the noise. Our investigations indicate that people feel less annoyed if they have trust in these institutions.
Can we draw any practical conclusions from this finding?
Yes, it could certainly be used for noise abatement planning in the future, for example by integrating the residents to a greater extent in the process. A concrete example: since April 2015 there have been so-called noise breaks at Frankfurt airport. Alongside the six-hour night flight curfew, this is an attempt to provide a further hour of relief in some areas by restricting the use of certain runways in the evenings in the hour before or in the morning in the hour after the curfew. This means that some regions are relieved between 10 and 11 in the evening and others between five and six in the morning. This is not possible everywhere or all the time, because it depends, for example, on the direction of the wind which runways are available. I still think it is a good idea to inform the residents about such measures. Ideally they should also participate wherever possible in the decisions on noise abatement measures.
In conclusion, a personal question: you have been working for a long time on the effects of traffic noise. Has this changed how you react to noise yourself?
Yes and no. Where I live, for example, there is no loud air traffic noise. But I do tend to notice more than before when a plane flies over me. Then I look up and think: that's still ok. Let's see what it's like in 10 years. This means that I have become more attentive, but the noise doesn't bother me any more than it ever did.