Acoustics expert: You can`t kill the noise, but you can manage it

According to the World Health Organization (WHO), one in five Europeans is regularly exposed to such a level of sound at night that can significantly contribute to the deterioration of health. Many studies prove the harmfulness and of noise and the annoyance it causes. In people exposed to excessive noise, it causes negative emotions, sleep disorders, it leads to exhaustion. It not only has a negative effects on psychosocial well-being, but also destroys health.

Prof. Janusz Kompała from the Department of Acoustics, Electronics and IT Solutions of the Central Mining Institute in Katowice says that the problem of noise is very complex, and planning should play a key role in solving it. According to the expert, noise can not be eliminated, but it can be managed properly.

According to Prof. Kompała, the problem of noise will continue to grow as long as politicians - and not experts - make decisions concerning planning new roads or railways. He notes that economic issues are usually decisive in such projects. This is the case, for example, with acoustic screens, commonly installed by Polish roads and railway tracks. Unfortunately their quality leaves much to be desired, the expert says.

"Some of them, despite the intentions of their creators, even worsen the situation of people living in their vicinity. Sometimes the screens stop some noise, but the remaining part is transformed into vibrations of the screens themselves. This changes the type of noise: a new source is created that generates low-frequency sound. People do not hear it, but it can be detrimental to their health" - explains Prof. Kompała.

The expert says that the most troublesome noise is associated with transport. "Nowhere in the world is the flow of cars directed into urbanized areas. It is good practice to set up underground routes, or routes outside large residential clusters" - he emphasises. According to the expert, for example, running the A4 motorway through Katowice "was a shot in the foot in terms of acoustics".

The professor emphasises that it is extremely difficult to reduce noise, especially in very tall buildings. In their case, even well-mounted acoustic screens often do not help.

Will the large scale use of electric cars reduce noise problems in our environment? "Such vehicles are definitely quieter, but this can generate other problems, for example associated with the blind or visually impaired in the city, whose safety depends on the sense of hearing, among other things. In Japan, where there are more electric cars than in Poland, additional sound sources are installed - so that pedestrians can hear them" - says Prof. Kompała.

The expert points out that in some cases, the noise caused by trains can be much more annoying, because people adapt more easily to the sound of constant intensity (like the noise of continuous car traffic). "The +stop and noise+ type, one that appears and disappears, like the noise generated by trains passing by buildings, is much more annoying" - he says. Traffic on the tracks is smaller than the road traffic, so it is much easier for people to notice the sound of a passing train. It can even cause psychoacoustic nuisance - awaken from sleep, irritate and thus significantly contribute to the deterioration of health.

Residents of neighbourhoods adjacent to airports sometimes complain about the noise caused by planes during takeoff or landing. Airplanes cover the majority of their route several thousand meters above the ground - their sound is barely audible and usually does not cause discomfort. According to the expert, in the near future we should not expect improvement of the situation, or a revolution such as the development of a new generation of very silent engines. "However, noise annoyance can be reduced by locating airports outside cities. It is also important to properly map the flight routes" - he says.

From year to year, there are more and more sources of sound in the world, including those that people perceive as noise. The scientist emphasises that noise is often subjective - it is a sound that disturbs a given person and constitutes an individual feeling. "We are becoming more and more acoustically expansive to the environment and, at the same time, more and more handicapped as a population, in terms of the auditory capability. As a result, we need stronger sound stimuli to react, and the circle closes" - the scientist concludes.

PAP - Science in Poland, Szymon Zdziebłowski

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