Please see important studies with their web links at bottom of page ~
The sound turbines produce is similar to a light whooshing or swishing sound. The sound of the blowing wind is often louder. The best test is always to experience the noise from a turbine for yourself. You will find that it is perfectly possible to stand underneath a turbine and have a normal conversation, without raising your voice.
There are two potential sources of noise: the turbine blades passing through the air as the hub rotates, and the gearbox and generator in the nacelle. Noise from the blades is minimized by careful attention to the design and manufacture of the blades. The noise from the gearbox and generator is contained within the nacelle by sound insulation and isolation materials.
Distance from the wind turbine, height of the wind turbine relative to the surrounding topography, the quality of the sound (repetitive low frequency sound), wind conditions, and wind direction all affect how the wind turbine noise affects people. Research done on wind turbines, airport and other sources of noise indicates that annoyance levels are difficult to assess. However, taking in account the above factors as well as careful measurements need to be considered when siting wind turbines near residential properties.1
According to studies performed by the British Wind Energy Association turbine noise level should be kept to within 5 dB(A) of the average existing evening or night-time background noise level.2 Massachusetts law and the Cape Cod local Bylaws will not allow sound levels of 10 dB(A) over ambient sound at property lines. According to the Massachusetts Department of Energy, “Noise impacts are regulated by municipalities as well as the Massachusetts Department of Environmental Protection (MassDEP), and should not be a factor for wind projects sited an appropriate distance from residences.3
There’s been a case made for the existence of an illness called “Wind Turbine Syndrome”. Infrasound, sound at such low frequency that it can’t be picked up by the human ear, is the primary issue for those concerned about wind-turbine syndrome. While the illness and the symptoms are still being debated, at present there are well over 10,000 wind turbines installed and operating in North America, and tens of thousands of people who live and work in proximity to these wind turbines. Of these individuals, a very small number have claimed that their health has been impacted by wind turbines. These reputed incidences are restricted to windfarm installations with multiples of turbines. However, surveys of peer-reviewed scientific literature have consistently found no evidence linking wind turbines to human health concerns.4
References:
1. Dr. Dora Mills, MD, MPH Maine CDC/DHHS
http://www.maine.gov/dhhs/boh/wind-turbines-neuro-acoustical.shtml
2. British Wind Energy Association
http://www.bwea.com/ref/noise.html
3. Mass Executive Office of Energy and Environmental Affairs
4. Canada Wind Energy Association
http://www.windisgood.ca/site/no_evidence.pdf
Review papers included:
“Infrasound from Wind Turbines – Fact, Fiction or Deception?” by Geoff Leventhall
“Wind Turbine Facilities Noise Issues” by Dr. Ramani Ramakrishnan for the Ontario Ministry of the Environment
“Wind Turbine Acoustic Noise”, A White Paper by Dr. Anthony Rodgers at the University of Massachusetts at Amherst.
“Research into Aerodynamic Modulation of Wind Turbine Noise”, University of Salford, UK, July 2007
“Health impact of wind turbines” , prepared by the Municipality of Chatham-Kent Health & Family Services Public Health Unit
Energy, sustainable development and health, World Health Organisation, June 2004
Additional References and Reports:
- “Wind Turbines and Health”, a 2010 study conducted by the Australian National Health and Medical Research Council
- “Understanding the Impacts of Wind Turbine Sound”, webinar #2 given by the federally funded NEWEEP, New England Wind Energy Education Program. The materials have been posted at the following link by July 27th http://www.windpoweringamerica.gov/newengland/past_webinars.asp
- “Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine” A report from the U.S. Department of Energy Lawrence Berkeley National Lab can be accessed on the LBNL website: http://eetd.lbl.gov/ea/emp/reports/lbnl-3562e.pdf
A report from the Chief Medical Officer of Health, Ontario, Canada. May 2010.
A report from the Acoustic Ecology Institute. November 2009.