An evaluation of how nightly variations in wind turbine noise levels influence wrist actigraphy measured sleep patterns
Health Canada's Wind Turbine Noise and Health Study assessed self reported and objective measures of sleep on a sub sample of the study's 1238 participants. The data analysis indicated that calculated long term outdoor wind turbine noise (WTN) levels up to 46 dBA did not have a significant influence on the evaluated measures of sleep (Michaud et al. 2016, Sleep 39, 97 109) A more refined analysis is being conducted to assess wrist actigraphy measured sleep patterns in relation to nightly variations in wind turbine operations. Variations in turbine operations (i.e. RPM and electrical power) were used to calculate WTN levels in 10 min intervals and time synchronised with sleep watch data collected in 1 min epochs. The 10 min sound levels and daily sleep diaries (relied upon to adjust for closed or open windows) were used to estimate indoor A weighted WTN levels. The correction factor used to obtain indoor sound levels was derived from a series of field measurements designed to investigate the outdoor to