Sonus Infrasound Report for Cape Bridgewater & Clements Gap Wind Projects

Infrasound Measurements from Wind Farms and Other Sources
Prepared for Pacific Hydro 2010
Measurements performed at Clements Gap and Cape Bridgewater

Sonus, one of the wind industry’s preferred acoustical companies, performed a study of infrasound at two Australian wind farms — Clements Gap in the mid-north of South Australia and Cape Bridgewater in the coastal region of south-western Victoria, using below ground methodology. Infrasound was also measured in the vicinity of a beach, the coastline, a central business area and a power station using the below ground methodology.

The measurement results indicate that the levels of infrasound in the vicinity of the two Australian wind farms are:

  • well below the perception threshold established in International research as 85 dB(G); and
  • of the same order as other International infrasound measurement results (a table summarising the results of other measurements is provided in this study); and
  • of the same order as that measured from a range of sources including the beach, the Adelaide Central Business District and a power station

Sonus’s conclusions are reproduced here:

The following conclusions can be made from the results of the study:

  • Wind turbines generate infrasound, however, measurements made both outside and inside and at a variety of distances significantly less than separation distances between wind farms and dwellings, indicate the infrasound produced by wind turbines is well below established guideline perception thresholds;
  • The level of infrasound that has been measured in both a rural coastal and an urban environment is of the same order as that measured within 100m of a wind turbine.

Download the Sonus report →

Download Acoustician Steve Cooper’s critique of the Sonus Report →