Correspondence (reply): In Reply

We are delighted at the positive response to our article (1) and express our warmest thanks to Prof. Müller, who raises important current aspects. He quite rightly points out that research on the effects of environmental noise should not be restricted to the health effects of “average” noise—as reflected by average sounds levels. For this reason, we made it clear in our article (as we have done in other publications [2]) that for assessing aircraft noise, particular attention should (also) be paid to maximum noise levels. The same is likely to be true for the small aircraft and helicopters mentioned by Prof. Müller. However, next to no research results have been published on this topic. We agree with Prof. Müller explicitly that research should not be restricted to the “classic” types of traffic noise. Future use of airspace and related health consequences of noise constitute an important topic for research and preventive regulation.

At this point, please allow us to mention a related topic that has barely been discussed in scientific discourse to date. Research into noise-related extraaural disease risks should not be restricted to single sources of noise. In addition to the comprehensive consideration of different—and also new—sources of noise, it is crucial to consider the combined effect of various noise sources. Our own research results suggest that, if several noise sources add up to a combined effect, the health risks could be considerably higher than expected from the common energetic summation of the noise pressure levels (3).