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Wind Farm noise, in common with noise generally, affects different people in different ways, but the evidence suggests there is rarely a problem for people living more than 1-1.5 miles from a turbine.
- For many people living relatively close to turbines, the noise does not present a problem. For those who are annoyed by the noise, it is overwhelmingly the “swish, swish, swish” of the turbines which troubles them.
- For people who are not able to shut out the noise, the problem can be exacerbated by the rotating blades and the dancing shadows of turbines. This can mean that the noise from turbines can be much more intrusive that other noises of a similar decibel level.
- For some people the impact of turbines can be overwhelming.
- The noise can be a particular problem in rural areas where background noise levels are low.
- The infrasound content of wind turbine noise is too low to be heard by most people.
- At times, low-frequency will form an audible, but not major part, of the “swish” sound of the turbines and can, for people sensitive to low-frequency noise, create additional problems. But the lowfrequency content of wind turbine noise is no greater than the low-frequency component found in several other noise sources and can only usually be heard down wind of a turbine when there is a fair bit of turbulence.
- However, low-frequency may be underestimated because of the persistent use of ‘A’ weighting in measuring the noise, rather taking ‘C’ weighted measurements.
- Research by medical doctors has unearthed persistent complaints from people saying they not only hear the noise from wind turbines, but can “feel” disturbance in their bodies. This has lead to complaints of illness. The symptoms people are complaining about are very similar to those associated with vibroacoustic disease. The suggestion is that the unique combination of noise (containing an element of low-frequency) and the strobing effects of the flickering blades, is having a physical effect on some people.
- Modern turbines are mechanically quieter, but there is convincing evidence that the noise they emit is being underestimated because measurements continue to be taken at a height of 10ft from the ground, thereby underestimating the speed of the wind (particularly at night) at the top of the large, modern turbines, over 100 metres high.