Understanding the Evidence: Wind Turbine Noise2 was published in 2015 by the Council of Canadian Academies’ Expert Panel on Wind Turbine Noise and Human Health, in response to a request from the Government of Canada for an assessment of the relationships between wind turbine sound and health effects. The authors researched the available scientific literature, web sites, and case law on this topic. Based on that review, the report attempts to summarize the current state of knowledge of wind turbine noise. The report’s authors focused on “causal relationships” between noise and health effects. A causal relationship is one in which one event is caused by another event.