Kelley et al, A Methodology for Assessment of Wind Turbine Noise Generation, 1982
As early as 1982, authors find that low frequency noise is the major cause of adverse health effects for residents living near wind and gas turbines.
N.D. Kelley, R.R. Hemphill, H.E. McKenna, Solar Energy Research Institute, Colorado
This research paper provides a detailed analysis of a series of acoustic measurements taken near several large (for the time) wind turbines (100 kW and above) and identifies the maximum acoustic energy as being concentrated in the low frequency audible and sub-audible ranges, usually less than 100 Hz. The paper shows that even at a fraction of the size of today’s 3, 3.5 and 4 MW turbines, there was still measurable ‘annoyance’.
In conclusion the authors suggest that they “have presented evidence to support the hypothesis that one of the major causal agents responsible for the annoyance of nearby residents by wind turbine noise is the excitation of highly resonant structural and air volume modes by the coherent, low frequency sound radiated by large wind turbines”.