I live in a building where a ventilator is constantly causing a low frequency sound. It is very soft, but deafening, I developed Tinitus. We can’t hear low frequencies very well so they sound soft, it is also hard to locate them, I have not managed to find the source. So I am stuck with the option to add sound proofing to my appartment, wear ear plugs or slowely go deaf.
Our brain is quite fragile. It has the consistency of soft butter. It is protected from the outside world by being ‘suspended’ in a liquid inside our skull. Vibrations can travel through the skull and liquid and brain just like they do through walls and doors and floors. The wave travels as a movement of contraction and expansion of the tissue, and this can break some neural pathways. We are all familiar with what happens when you wack someone against their skull, they can lose consciousness. Boxers and Footbal players and Rugby players can all suffer from brain damage, slow speech, ‘brainfog’.
A self professed expert on this topic assured me there is no brain damage from say heatpumps. But he was talking about easily recognizable debilitating brain damage, so parts of the brain actually gone. That is not what I think we should worry about. What we should worry about is erosion of pathways due to constant movement of the neural tissue, something that is very unnatural. As long as the movements are slow enough to allow the liquid ‘suspension system’ to help the brain accelerate and not rip apart, you can’t really say there is a problem. Horseback riding or driving in a noisy car come close.
Some publications that may be relevant
“They team believe they have shown for the first time that brain injuries are caused by vibrational modes induced by impacts”
Ok this is by impacts, but they show that damage is done by waves traveling through the brain.
“”Low-frequency sound exposure has long been thought to be innocuous, and this study suggests that it’s not,””
” the subjects, regardless of the LFN sensitivity, showed tendency to make more errors during exposure to LFN than in the reference noise”
“The subjects categorized as high-sensitive to LFN also showed poorer performance than others during exposure to LFN in the Stroop Color-Word Test”
From this we can conclude low frequency noise disturbs brian function. How? By causing damage?
Mostly seemingly annecdotal evidence of the effect of infra sound on health.
“Positron emission tomography measurements revealed that, when an HFC and an LFC were presented together, the rCBF in the brain stem and the left thalamus increased significantly compared with a sound lacking the HFC above 22 kHz but that was otherwise identical.”