Wind turbine infrasound below the hearing threshold alters the brain – Charité study refutes official all-clear

Dr. Peter F. Mayer, tkp.at

The claim that infrasound from wind turbines is harmless as long as it cannot be heard is part of the standard repertoire of the wind industry lobby and the authorities. Scientific evidence of brain damage is denied.

For years, the WHO and numerous German institutions have repeated the same line: there is “no reliable evidence” that infrasound below the hearing threshold has physiological or psychological effects. A 2017 fMRI study from the Charité fundamentally challenges this claim. For the first time, it showed with imaging techniques that infrasound near the individual hearing threshold produces measurable changes in brain activity – in regions associated with auditory processing, emotional regulation and autonomic control.

The study by Markus Weichenberger and colleagues, entitled “Altered cortical and subcortical connectivity due to infrasound administered near the hearing threshold – Evidence from fMRI”, was published in PLoS ONE on 12 April 2017.

The experiment

14 healthy participants were examined in two sessions. First, the individual hearing threshold and loudness perception for a 12 Hz infrasound tone were determined. In the second session, the participants lay in the MRI scanner and underwent three resting-state fMRI measurements:

• without a tone
• with a 12 Hz tone just below the individual hearing threshold (near-threshold)
• with a louder tone above the hearing threshold, perceived as “moderately loud” (supra-threshold)

The analysis focused mainly on local connectivity (Regional Homogeneity, ReHo) and large-scale network connectivity (Independent Component Analysis, ICA).

The results

Stimulation near the hearing threshold showed significantly increased local connectivity:

• in the right superior temporal gyrus (STG), adjacent to the primary auditory cortex
• in the anterior cingulate cortex (ACC)
• in the right amygdala as well, with smaller cluster sizes

These effects occurred in comparison with both the no-tone condition and the clearly audible supra-threshold condition. The audible loud stimulation, by contrast, produced no comparable significant activations.

In addition, the ICA analyses showed changes in network connectivity: in the near-threshold condition the right amygdala was more weakly coupled to the sensorimotor network, while the right superior frontal gyrus was more strongly activated.

What this means

The authors themselves write that this is the first study to demonstrate that infrasound near the hearing threshold can trigger changes in neuronal activity in several brain regions – including areas of auditory processing as well as key regions of emotional and autonomic control. They explicitly speculate that continuous exposure to (sub-)liminal infrasound could have a pathogenic effect.

This is precisely where the explosive nature of the wind power debate lies. Industrial wind turbines produce inaudible infrasound with sound pressure levels that, at residential distances, are often typically in the range of 60–90 dB, depending on distance and sources.

The official position is: what you cannot hear cannot harm you. The Charité study shows the opposite: it is precisely the infrasound that is not consciously perceived that alters brain activity in regions linked to stress processing, emotional evaluation and autonomic functions.

The amygdala and the ACC play central roles in fear, stress and the regulation of the autonomic nervous system. Permanent, unconscious stimulation of these systems by infrasound from wind farms could explain why residents report sleep disorders, restlessness, palpitations, depression or a general feeling of illness – even though the sound is objectively “inaudible”.

The political dimension

Although the study has been publicly accessible since 2017, it is largely ignored or downplayed in the official statements of the Federal Environment Agency (Umweltbundesamt), state ministries and wind power associations. Instead, they point to the lack of audibility and fall back on the nocebo effect. The Charité researchers, however, did not measure subjective complaints but objective changes in brain connectivity using fMRI. That, by the way, is called natural science.

The study is small (14 participants) and short-term. It does not prove long-term health damage. It does, however, refute the central premise of the all-clear policy: that only audible sound is physiologically relevant. Anyone who continues to claim that infrasound below the hearing threshold has no effect is ignoring the neurophysiological data from the Charité.

The authors called for further, in particular longitudinal, studies. Politics, however, prefers to push ahead with the massive expansion of wind turbines and, with preposterous claims, denies the evident health damage caused by infrasound.

Everything you need to know about wind power in one book:

• Die Windkraft-Lüge. Was Windräder in Wahrheit anrichten (The wind power lie: what wind turbines really do) Dr. Peter F. Mayer, Torsten Engelbrecht. TKP Verlag, 1st edition 2026. Paperback ISBN 978-3-9506363-0-7.

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This article first appeared in German on tkp.at – with kind permission of Dr. Peter F. Mayer.
Cover image: 4lb / Pixabay