The medical doctors, audiologists and acoustical professionals from the USA, Canada, Denmark and the UK undertook “extensive review, analysis and discussion of the large body of peer-reviewed literature” on the sounds produced by wind turbines.

“The sounds emitted by wind turbines are not unique; there is no reason to believe, based on the levels and frequencies of the sounds, that they could plausibly have direct adverse physiological effects,” it concludes.

If sound levels from wind turbines were harmful, it would be impossible to live in a city given the sound levels normally present in urban environments, the professionals explain to the American Wind Energy Association (AWEA) and the Canadian Wind Energy Association (CanWEA).

“Sub-audible, low frequency sound and infrasound from wind turbines do not present a risk to human health,” although the authors concede that “some people may be annoyed at the presence of sound from wind turbines; annoyance is not a pathological entity.”

For 30 years, people have been living near the 50,000 wind turbines in Europe and the 30,000 in North America, and the vast majority have had a positive experience with no ill effects, notes Wind Turbine Sound & Health Effects: An Expert Panel Review. There are more than 120 GW of wind turbine capacity installed around the world and the technology enjoys “considerable public support but it also has its detractors.”

“The ground-borne vibrations from wind turbines are too weak to be detected by, or to affect, humans,” it concludes. “There is no reason to believe, based on the levels and frequencies of the sounds and the panel’s experience with sound exposures in occupational settings, that the sounds from wind turbines could plausibly have direct adverse health consequences.”

The panel reached agreement on three key points:

1. There is nothing unique about the sounds and vibrations emitted by wind turbines.
2. The body of accumulated knowledge about sound and health is substantial.
3. The body of accumulated knowledge provides no evidence that the audible or subaudible sounds emitted by wind turbines have any direct adverse physiological effects.

There are complexities involved in the varied human reactions to sound, particularly sounds that modulate in intensity or frequency, and most complaints about sound from wind turbines relate to the aerodynamic sound component (swish sound) produced by the blades.

The report summarises physical and psychological variables that may influence adverse reactions, including the ‘wind turbine syndrome’ and vibroacoustic disease (tissue inflammation and fibrosis associated with sound exposure), which have been claimed as causes of adverse health effects.

“Sound from wind turbines does not pose a risk of hearing loss or any other adverse health effect in humans,” it states.

“Subaudible, low frequency sound and infrasound from wind turbines do not present a risk to human health” and “a major cause of concern about wind turbine sound is its fluctuating nature; some may find this sound annoying, a reaction that depends primarily on personal characteristics as opposed to the intensity of the sound level.”