Decibel: A unit of measurement for sound. Maximum wind turbine noise is about 103 decibels, roughly equivalent to a snowmobile. At a distance of 400 meters, it can be about 40 decibels, the equivalent of a refrigerator humming.
Nocebo effect: Opposite of the placebo effect; said to occur when a person experiences negative symptoms induced by negative expectations. Some wind-power advocates say it explains the complaints about turbines.
Shadow flicker: Also known as the “flicker effect” or “light flicker,” the strobe-like effect that occurs when sunlight shines through the spinning blades of a wind turbine.
Turbine: (Pronounced TUR-bin or TUR-bine) A device that converts wind into electricity. It typically consists of three blades rotating about a horizontal axis on a tower. It’s not the same as a windmill, which harnesses wind power to pump water or mill grain.
Wind Turbine Syndrome: Described in a book of the same name by Dr. Nina Pierpont, which said many people who reside within 1.25 miles of wind turbines get sick and end up with “acoustically toxic” homes. Many wind-power supporters are skeptical of those assertions.
SOURCES: US Department of Energy; Massachusetts Wind Turbine Health Impact Study; National Institutes of Health; National Oceanic and Atmospheric Administration