‘What you can’t hear, can’t hurt you’ notion shown to be false
 
The wind power industry, Health Canada, and the Ontario government insist that infrasound cannot be heard, and therefore it cannot hurt you.
CanWEA went so far as to pay for a study done by MIT in 2014, that concluded infrasound near wind turbines does not exceed audibility thresholds* and is therefore not a health risk.
Turns out, they are wrong.
All of them.
A paper just published by a team of German researchers, believed to be the first of its kind, documented “changes of brain activity across several regions in response to prolonged, near-threshold IS [infrasound] …”
The peer-reviewed paper, Altered cortical and subcortical connectivity due to infrasound administered near the hearing threshold – Evidence from fMRI, was published by a team of researchers led by Markus Weichenberger of the Max Plank Institute for Human Development.
“For decades,’ the research team wrote, “it has been a widely held view that IS [infrasound] frequencies are too low to be processed by the auditory system. … Meanwhile, there seems to be a growing consensus that humans are indeed receptive to IS and that exposure to low-frequency sounds can give rise to high levels of annoyance and distress.”
The authors then stated that the idea that sound needs to be perceived in order to exert effects on humans “falls short when aiming at an objective risk assessment of IS.”
The team then set out to investigate whether IS “near the hearing threshold” can affect brain activitiy and what the effects of stimulation might be.
An excerpt:
” … our results also allow us to draw some preliminary conclusions on potential long-term health effects associated with (sub-)liminal IS stimulation. It has been reported in several studies that sustained exposure to noise can lead to an increase of catecholamine- and cortisol levels [114–116]. In addition, changes of bodily functions, such as blood pressure, respiration rate, EEG patterns and heart rate have also been documented in the context of exposure to below- and near-threshold IS [117–118]. We therefore suggest that several of the above mentioned autonomic reactions could in fact be mediated by the activation of brain areas such as the ACC and the amygdala. While increased local connectivity in ACC and rAmyg may only reflect an initial bodily stress response towards (sub-)liminal IS, we speculate that stimulation over longer periods of time could exert a profound effect on autonomic functions and may eventually lead to the formation of symptoms such as sleep disturbances, panic attacks or depression, especially when additional risk factors, such as an increased sensibility towards noise, or strong expectations about the harmfulness of IS are present.”
And, ” Transient upregulation of these brain areas in response to below- or near threshold IS may thus reflect an initial stress response of the body, eventually promoting symptom formation as stimulation occurs repeatedly and additional risk factor[s] come into play…”
Read the entire open-access paper here.