Propagation thresholds and measurement of infrasound to establish separation distances from wind farm turbines to residences

Of all the issues surrounding noise emissions from wind farms, the question of the potential for annoyance and adverse effects from low frequency sound is one of the most topical. Anecdotal literature is replete with statements concerning the effects of infrasound and low frequency noise. In this paper we present objective methodologies to measure and assess infrasound and low frequency noise in the context of wind farm emissions. The methodologies are reviewed with respect to three wind farms: one each in New Zealand, Victoria (Australia) and South Australia. The South Australian review incorporates data from a recent South Australian EPA wind farm study. The calculations for recommended stand-off distances from wind turbines to residences are presented. The distances are based on the threshold of annoyance and physiological effects threshold anticipated for different turbines and frequencies.