Infrasound at or under perception threshold does not cause acute physical reactions

UBA experimental study does prove annoyance effect

laufender VentilatorClick to enlarge
Equipment to produce energy and ventilation systems raise complaints about infrasound
Source: 3dmentat / Fotolia.com

An experimental study by the German Environment Agency (UBA) found no correlation between infrasound immissions at or below the perception threshold and acute reactions on the human body. However, the test persons classified the infrasound sounds as "somewhat" to "moderately" annoying. The annoyance was considered higher the closer the sounds came to the perception threshold and into the low-frequency audible sound range. Whether or not someone was already exposed to infrasound or low frequency sounds in their living environment did not play a role in influencing physical reactions and annoyance.

The experimental study was conducted under extensively controlled conditions on a former barracks site near Flensburg. A total of 44 persons were exposed to four different types of infrasound within approximately eight hours. Each sound exposure lasted 30 minutes. The physiological parameters heart rate, blood pressure, cortical activity and balance perception were measured both during and after the noise scenarios. irradiation. No statistically significant changes due to infrasound were found. Acute feelings of annoyance were assessed by means of questionnaires. The infrasound sounds were in the frequency range from 3 Hz to 18 Hz with sound pressure levels between 105 and 85 dB. The sounds thus represented a spectrum below, close to and just above the currently defined perception threshold. One of the noises was amplitude modulated. Amplitude modulations can occur, for example, in the emission of infrasound from wind turbines.

Stationary devices such as refrigerators, heat pumps and technical equipment e.g. wind turbines or biogas plants emit low-frequency sound including infrasound. Infrasound is defined as sound waves in the frequency range below 20 Hertz and is not perceptible to most people through hearing.

There is little scientific knowledge about the negative effects of infrasound below the threshold of perception. The UBA experimental study addresses this question. However, the study was conducted as an experimental study with a small number of test persons and a comparatively short exposure time to synthetic pure infrasound signals. Therefore, the research results cannot be generalized and no possible long-term health effects of infrasound immissions in the residential environment can be derived. In order to identify possible as yet unknown long-term effects, an epidemiological long-term study in the residential environment is required. UBA therefore intends to conduct a preparatory research project on this topic in the coming year.

Umweltbundesamt Hauptsitz

Wörlitzer Platz 1
06844 Dessau-Roßlau
Germany