Finally, the Maine public is getting some better information on wind shear and turbine noise.
This is just a short news clip, but it mentions the proper reason for the unplanned noise.
Without understanding this complex phenomenon, you can't understand turbine planning, but Maine "Home Rule" planning regulations basically require amateur planning of wind power proposals, and have resulted in numerous restrictive ordinances, town by town, with many more in the pipeline, some of which essentially prohibit even the smallest and most innocuous of turbines (such as the Southwest Wind Power Air X) for noise planning reasons.
There's nothing wrong with Home Rule, or amateur involvement in planning, but we should understand that some things are complex and can't be easily understood without at least some hard work.
See the last post but one for the best information I've seen yet in the public domain.