It is the only essential problem, but at the same time quite easy to deal with. Wind turbine emitted noise can be classified in two types, depending on its origin: 

1. Mechanical 
2. Aerodynamic 

Mechanical noise mainly comes from the rotating mechanic parts (gear box, electric machine and bearings) whereas aerodynamic noise comes from the blade rotation. The modern wind generators are very quiet machines comparatively with their power output and with the continuous improvements by constructors they can always become less noisy. The confrontation of the generated noise is either done in its source or along the way. Mechanical noises are minimised by initial design. (cogwheels of sidelong dentition), or with internal sound-insulating tile in the shell of the manufacture. On the other hand the aerodynamic noise is minimized with careful design of blades by the constructors. 

The level of the perceptible noise from a modern wind turbine in a distance of 200 metres, is substantially smaller than what corresponds to the level of noise of the environment of a small town and of course does not constitute a source of nuisance. Given the legislated requirement that the installed wind generators have to be situated in a minimal distance of 500 metres from any settlements, the level is still lower and it corresponds to that of a quiet room. Moreover, in wind speeds that wind generators function, the surrounding noise (noise of wind in trees and bushes) overlaps any noise that emanates from the machines. 

Therefore, wind farms do not;

•  increase of the existing level of noise 
•  expose inhabited areas in high level of noise

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