RIBEolh

Wind energy is expanding rapidly in France as elsewhere in the world, but the population is worried about the health impacts of wind turbine noise and some people are more annoyed than the sound field measurements would suggest. The annoyance is often described as resulting from infrasounds (IS) whereas the acoustic pressures of IS emitted by wind turbines would be below the perception thresholds. However, the inaudibility of IS does not exclude their action on the inner ear or the central nervous system. The WHO guidelines on environmental noise published in October 2018 highlight that evidence on the health effects of noise from wind turbines is either non-existent or of poor quality. In this context, the objectives of RIBEolh are: - To assess the health effects of audible noise, in particular low-frequency sounds (LFS), but also IS, emitted by wind turbines. - To better understand the auditory mechanisms associated with the perception of IS and LFS emitted by wind turbines, and more particularly the sensations related to sound intensity (loudness) and to amplitude modulations, and their link with annoyance. - To better understand the effects of IS on the inner ear or central nervous system, which may explain certain symptoms sometimes described by subjects exposed to IS and who complain about them. To address these objectives, RIBEolh is based on a methodology structured in two complementary parts. A first phase is based on the implementation of an epidemiological study to better understand and quantify the health effects of noise emitted by wind turbines. The second phase is based on a psychoacoustic and physiological study, conducted under controlled conditions, to understand the auditory mechanisms associated with annoyance caused by IS and LFS emitted by wind turbines. The epidemiological study will include about 1200 residents around wind farms in France. Information concerning their health status will be obtained by means of a questionnaire (sleep disturbances, hypertension, psychological disorders, stress and annoyance in particular), and by measuring body movements during sleep, blood pressure, heart rate and cortisol concentration (stress marker). The exposure of participants to audible noise, in particular LFS, but also to IS, emitted by wind turbines, will be estimated using noise prediction engineering models. Acoustic measurements will be made to validate the model used. The psychoacoustic and physiological study will consist in carrying out psychoacoustic and physiological measurements in a controlled environment using signals measured and synthesized by a physical model for different operating conditions of wind turbines. The psychoacoustic work will focus on loudness and auditory sensations related to amplitude modulations in order to understand their relationship with annoyance. Finally, physiological measurements of cochleovestibular responses will be performed in participants submitted to IS to test the hypothese that non-audible IS may affect hearing and/or balance. RIBEolh will advance knowledge of the health effects of audible noise, in particular LFS, but also IS, emitted by wind turbines, and how they are felt. Epidemiological results will complement the very few studies in this area. Beyond the noise of wind turbines, the results on the perception of IS and LFS will make it possible to improve our knowledge of the processes of perception or annoyance concerning these frequencies, whatever the type of noise, and of the physiological mechanisms in the inner ear that induce their perception.