The noise from wind farms can have subtle effects on sleep, including changes to the amount of time spent in a deep sleep. Researchers at Flinders University say studies of wind farm turbine noise show it can have small effects on our sleeping patterns. The Adelaide Institute for Sleep Health has looked at the results of five sleep studies in a new review paper published in the international Journal of Sleep Research. Lead author Tessa Liebich says when comparing wind turbine noise to quiet background noise, there are no systemic effects on time taken to fall asleep, total sleep time, time spent awake during the night and time spent asleep relative to overall time in bed. “However some more subtle effects on sleep in some objective studies were established including shifts in sleep stages, less time spent in deep sleep and more time spent in light sleep.” Flinders University researchers are also studying sleep patterns in more than 70 volunteers in a controlled laboratory study with the final results due mid-2021. Senior author Dr Gorica Micic says limited knowledge and data in the area emphasises the need for further well-controlled experimental studies to provide more conclusive evidence regarding wind turbine noise effects on sleep. “Environmental noises, such as traffic noise, are well known to impact sleep,” Dr Micic says. “Given wind power generation is connected with low frequency noise that can travel long distances and more readily into buildings, it is important to better understand the potential impacts of wind turbine noise on sleep.” Dr Micic said the latest study aimed to comprehensively review published evidence regarding the impact of wind turbine noise on the most widely accepted objective and subjective measures of sleep time and quality. But subjective sleep outcomes were not sufficiently uniform for combining data or comparisons between studies. “Nevertheless, the available self-report data appeared to support that insomnia severity, sleep quality and daytime sleepiness can be impacted by wind turbine noise exposure in comparison to quiet background noise.” But researchers said any firm conclusions were difficult to draw given the inconsistent study methods.