"People who live next to a wind turbine have reported being disturbed in their sleep, but we have no scientific support for it," says Kerstin Persson Waye, professor of environmental medicine at the University of Gothenburg. 

Now the researchers can establish that there is a link.  

- I think the result is very interesting. Partly because we see the impact at such low levels, and partly because we see that objective data is supported by what the test subjects themselves say they experienced.  

50 people in the study

50 people participated in the study. Twenty-four people lived at most one kilometer from one or more wind turbines for at least one year. The other 26, did not live near wind turbines. 

Participants were allowed to sleep in a sound environment lab for three nights. There they were exposed to wind noise. Brain activities, eye movements and heart rate were recorded to see how the participants reacted to a quiet night compared to one night where they were exposed to four different periods of sound from wind turbines.

Delayed and shorter dream sleep

One night in wind power sound gave delayed and shorter dream sleep. In addition, participants reported that they experienced worse sleep.

- The study gives us information we need to either maintain or change the guidelines that exist, says Kerstin Persson Waye. 

The Swedish Environmental Protection Agency, which is responsible for how the environmental code is to be applied when it comes to outdoor wind noise, is currently conducting a review of the guidelines.

"Can not exclude a certain impact"

- The conclusion we draw from the study is that it cannot be ruled out that there may be a certain impact on sleep when it comes to wind power sound, says Lisa Johansson, technical manager for the Swedish Environmental Protection Agency. 

Despite this, no changes are expected with regard to noise guidelines. 

- We see that our level is good for wind turbine noise if you look at WHO guidelines, says Lisa Johansson. 

In the clip you can accompany Kerstin Persson Waye into the sound environment lab in Gothenburg.