Tilting at Windmills: The power of expectations to influence symptom reporting by people exposed to wind turbine sound

Abstract

Background: A number of people living in the vicinity of wind farms are reporting health complaints they attribute to exposure to sub-audible wind farm sound (infrasound) generated by wind turbines. A causal link between exposure and symptoms is not indicated by empirical evidence. Evidence indicates symptom reporting tends to arise in locations where residents are exposed to misinformation that wind turbine generated infrasound poses health risks. This suggests that health complaints may be explained by the nocebo effect, whereby health concerns inform negative expectations which, in turn, trigger symptomatic experiences. Objective: It was a specific research aim to investigate whether negative expectations, formed from health warnings about wind farm infrasound, might be providing a pathway for symptom reporting and noise annoyance in community settings. It was a further aim to explore whether creating more positive expectations about wind farm sound has the potential to alleviate symptom reporting and annoyance reactions in wind farm communities. Method: Research involved a series of experimental studies in which healthy volunteers were concurrently exposed to infrasound and audible wind farm sound, while variously reporting on current symptoms, mood, and annoyance reactions, during two exposure sessions. Expectations about wind farm sound were manipulated prior to exposure sessions. Results: Exposure to media health warnings, about wind farm sound, triggered symptom reporting and noise annoyance during simultaneous exposure to infrasound and audible wind farm sound. However, participants were less likely to experience nocebo responses, if they had been previously exposed to positive health information about infrasound, or were made aware that reported symptoms could be explained by the nocebo effect. Further, individuals given information outlining the possible therapeutic effects of infrasound, reported a significant reduction in symptoms from baseline, and did not experience noise annoyance, even if they were subjectively noise sensitive. Conclusion: Results indicate that negative expectations, triggered by health warnings about wind farm sound, may be providing a pathway for symptom reporting in wind farm communities. Overall, findings also indicate that creating more positive expectations about wind farm sound may ameliorate health complaints and reduce annoyance reactions in community settings.