One of the developers of the French system ended up getting paralysed by his invention. It is completely useless for military purposes because such low frequencies cannot be directed at a target with any precision without the source being enormous and therefore easy to detect and destroy by more conventional methods. Low-frequency noise from wind turbines is a problem in some places because the sound can be very annoying. Beyond that, the effects will be negligible. John
The device described in that article operates at 2 to 4kHz where it is possible to have a reasonable amount of directivity from a practical sized source. The situation is totally different from infrasound at a few Hz. John
Depends on the distance between wind turbine and house, soil quality etc.
There are different rules of thumb how close wind turbines should be placed relative to inhabited areas.
One states that the distance from the wind turbine to the nearest house should be at least 20 times the turbine height. This will attenuate the infra sound and also limit sunlight flicker to only short periods in the morning and evenings when the sun is close to the horizon. That distance also reduces the risk of ice falling from the blades as well as dead birds hit by the turbine blades.
Building wind turbines too close to inhabited areas will reduce the general acceptance of wind power and renewable energy in general.
I was once setting up the equipment for a band and standing next to the base guitar speaker. I took the base guitar and played some chords to test the setup.
I did not notice that the volume control was close to maximum and felt quite uncomfortable in my internal organs due to the resonances.
After this event I always check the volume control before doing such tests :-).
In a bass guitar, the strings are quite close in frequency, so the difference frequency could be in the infra sound area. Apparently there were some non-linearity in the amplifier, speaker or human organs to generate such difference frequencies (and not just a long sequences of the multiple frequencies).
For centuries, medium size pipe organs can generate the feeling of very low tones (which would require huge pipes) by sounding two medium size pipes, which are close in frequency. Apparently the human physiology generates these 'difference frequencies'. To find such difference frequencies with a spectrum analyzer would require some non-linearity to generate difference (and sum) mixing products.
Driving over cattle grids is similar, though fortunately the duration is short.
(I suppose that's why cows don't drive over them.)
More cowbell !!
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