WIND farm noise is lower than most other sources of environmental noise according to the Victorian Department of Health.
An information brochure released last week on wind farms and health describes the main sound within 300m of a turbine as a mid-high frequency level "intermittent swish''.
"At the distance of most neighbouring residents, the level of sound from wind farms is lower than that of many other sources of environmental noise,'' the brochure says.
"Low frequency sounds may be more noticeable than the swish at distances further away from the turbine.''
However "infrasound is produced by the body at higher levels than many external sources, including wind farms'' so "humans have therefore been exposed to infrasound throughout our evolution''.
Individuals perceived and reacted to sounds differently and only audible sound could impact health, the department said.
Anti-wind farm group the Waubra Foundation's Sarah Laurie said "if people can't sleep, there is a serious problem''.
"That is the commonest problem reported by residents. The (VDH) have a duty of care to investigate,'' Dr Laurie said.
Yes 2 Renewables spokesman Leigh Ewbank said there was nothing new in the department's findings.
"It merely confirms existing peer-reviewed studies which rule out adverse health impacts," Mr Ewbank said.
"How many studies will it take before anti-wind farm campaigners stop spreading fear about this clean, renewable energy source?"