The findings could be a vital step in medical studies to determine if turbines can have serious health implications

Acoustics engineer Steven Cooper based his study on the Cape Bridgewater farm operated by Pacific Hydro and its effects on six residents in three houses.

Pacific Hydro had requested the research to measure noise and vibration to determine if certain wind conditions or sound levels caused disturbances identified by the residents.

The company released the report yesterday, but disputed the preliminary finding of a trend link between “sensations” reported by residents and turbine infrasound.

Mr Cooper collected data during eight weeks of  24-hour monitoring and concluded that when turbines were generating electricity they produced a “signature” sound that could be identified as an uncomfortable sensation inside and outside the dwellings.

All other wind farms would produce the same narrow-band sound range, he said.

Mr Cooper spoke to The Standard yesterday from Canada, saying his findings were the first in the world to determine a wind turbine signature and show an association with sensations experienced by humans.

“I’m not qualified to conduct medical research, that’s up to others,” Mr Cooper said.

“There is now opportunity to do further medical study because we now have a signal to measure from.”

Mr Cooper said he first set a scale of one to five for severity of sensations noted by residents and then analysed narrow-band sound from turbines, which showed a pattern. 

Sensations included headache, pressure in the head, ears or chest, ringing ears and racing heart.

Each of the residents was required to make diary notes for the eight-week study.

Mr Cooper said he was fortunate to have full co-operation from Pacific Hydro and rare opportunity to measure ambient sound when the wind farm was switched off.

His studies also showed a high correlation between wind speed and general noise levels, but not necessarily when the wind farm was operating. 

He will present his findings at a public meeting at Portland golf club on February 16.

Pacific Hydro has sent the report to stakeholders including government departments, politicians, environmental organisations and health bodies, which may trigger further studies into the issue.

Company executive manager of external affairs, Andrew Richards, said while the findings were acknowledged the meaning was unclear.

“In our view results presented in the report do not demonstrate a correlation that leads to the conclusion there is a casual link between infrasound frequencies and the ‘sensations’ experienced by the residents,” Mr Richards said.

He said the company’s analysis of the data did not support Mr Cooper’s conclusion of a trend line.