Sleeping people respond to both wind farm noise and road traffic noise, but not usually enough to wake them up, according to new Flinders University research.
Published in the Journal of Sleep Research, researchers used an electroencephalogram (EEG) to analyse the brainwaves of 23 young healthy people while they experienced 3-minute samples of wind farm noise and road traffic noise played at different noise levels (33, 38 and 43 dBA).
“These noise levels span the approximate range of recommended maximum average indoor and outdoor noise levels at night,” says lead author Claire Dunbar from Flinders Health and Medical Research Institute: Sleep Health.
“By noting changes in their brain waves, we found the participants responded similarly to both wind farm and road noise, especially when the sound was louder. Then, during light sleep, we found low-level wind farm noise caused a greater brain activation response, compared to road traffic noise played at the same noise level.”
However, the authors say the effects of the sounds were brief, with most participants’ brain waves returning to baseline sleep activity levels 30 seconds after the start of each noise, with very few people actually waking up, either briefly or for a prolonged period.
“This tells us the overall impacts of the noise on the participants’ sleep was relatively small,” says Ms Dunbar.
The research is an important step towards applying more sensitive brain signal analysis techniques, compared to traditional manual sleep scoring methods, the authors say. With the new approach, researchers can better understand the impacts of noise on sleep, particularly at low noise levels and with different noise characteristics, where sensitive methods are most needed.
“While this study shows there is a response to wind farm and road traffic noise while an individual is sleeping, more research using a similar technique with a larger group of people and longer exposure times is still needed to help better understand noise impacts on sleep and potential longer-term effects,” says Ms Dunbar.
The research is part of an ongoing series of studies being undertaken at Flinders University to investigate the effects of wind farm noise compared to traffic noise on different aspects of sleep.
‘EEG power spectral responses to wind farm compared with road traffic noise during sleep: A laboratory study’ by Claire Dunbar, Peter Catcheside, Bastien Lechat, Kristy Hansen, Branko Zajamsek, Tessa Liebich, Duc Phuc Nguyen, Hannah Scott, Leon Lack, Felix Decup, Andrew Vakulin and Gorica Micic is published in the Journal of Sleep Research. DOI: 10.1111/jsr.13517.
This research was supported by grants from the National Health and Medical Research Council and the Australian Research Council. Claire Dunbar acknowledges The Hospital Research Foundation for PhD scholarship support.
