When a sound is made, it spreads. And when it hits a hard surface that is far away, it bounces back and comes back to where the sound was made. That’s what we call an echo.
Infrasound is generated by wind turbines, air conditioners, and a host of natural phenomena.
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At the centre of claims about wind farms allegedly causing health problems is the infrasound that wind turbines generate as they turn in the wind. Infrasound is sound below 20Hz, which is generally inaudible…