HELSINKI: The low-frequency, inaudible sounds made by wind power stations are not damaging to human health despite widespread fears that they cause unpleasant symptoms, research published in Finland on Monday said. A number of studies have already concluded that the audible noise from the energy-generating windmills does not cause health impacts beyond annoyance and sleep disturbance in people living close by. However, the two-year Finnish project, commissioned by the government, examined the impact of low-frequency — or infrasound — emissions which cannot be picked up by the human ear. People in many countries have blamed the infrasound waves for symptoms ranging from headaches and nausea to tinnitus and cardiovascular problems, researchers said.