It could be worse. A lot worse.
Flinders University
.webp)
But importantly, the
new study also shows that wind farm noise isn't more disruptive to sleep than
road traffic, which was a little more disruptive at the loudest audio level but
not at more common levels.
Sleep researchers at
Flinders University have studied the impact of exposure to wind farm noise
during sleep in three new scientific publications to better understand its
impact on Australians.
The study played 20-second wind farm and road traffic noise samples repeatedly during participants sleep using 3 different sound pressure levels to compare their sleep disruption responses between the two different noise types.
On a separate night,
the study tested if longer 3-minute noise samples, including very low-frequency
wind farm infrasound alone, resulted in sleep disturbance.
The researchers also
found that wind farm infrasound at realistic levels was not audible to the
human ear during wake and produced no evidence of sleep disruption. These
findings were presented at the International conference on Wind Farm
Noise in Dublin on June 22, 2023 and are still to be journal peer
reviewed.
The project took 5 years to complete and involved over 460 sleep study nights from 68 participants who each spent seven consecutive nights in the sleep laboratory.
The participants were
recruited from four groups, including people living near a wind farm with and
without noise related sleep difficulties, a group of residents living near a
busy suburban road and people living in quiet rural areas.
"In order to
capture the most representative wind farm noise features and levels, we used
noise samples from long-term measurements of wind farm noise. These were then
reproduced in the sleep laboratory to replicate real-life noises in a much more
controlled environment than is possible in field studies, where wind and noise
conditions are highly variable. The study included direct sleep measurements
using electroencephalography (EEG) as well as hearing tests and a range of
daytime listening tests," says Dr. Bastient Lechat, one of several
acoustics experts on the research team.
Professor Peter
Catcheside, a sleep expert from Flinders University and the chief investigator,
says that the findings show that both wind farm noise and road traffic noise
disrupt sleep, depending mainly on noise loudness and sleep depth at the time
of noise exposure.
"However, at
realistic levels, these effects were quite small. We also found no evidence to
suggest that wind farm noise is any more disruptive to sleep than road traffic
noise. At the highest exposure level, road traffic noise was a little more
sleep disruptive than wind farm noise."
Professor Catcheside
says one of the study's aims was to determine if realistic levels of wind farm
infrasound could be heard by study participants during wake or show any sign of
EEG recorded brain activity changes when played during sleep.
"Our results
align with previous studies and showed that infrasound played at realistic
levels was not audible during wakefulness and produced no detectable EEG
changes during sleep. Infrasound is therefore unlikely to explain noise
complaints from wind farms, suggesting that other low frequency audible
rumbling and thumping components deserve more attention towards better
understanding wind farm noise effects on sleep."
Professor Catcheside
says that while this study provides strong evidence that wind farm noise is not
more disruptive to established sleep than road traffic noise, this does not
rule out that people who are particularly noise sensitive or annoyed may find
it more difficult to get to sleep when noise levels are noticeable.
This research was supported by grants from the National Health and Medical Research Council and the Australian Research Council.