How to determine the annoyance due to the wind turbine

In the study of annoyance due to wind turbines, the dominant approach takes into account only the noise generated by these sound sources. However, there are studies which show that such value alone is not enough to explain why for the majority of people living near wind turbines their noise is extremely annoying, despite the fact that the measured sound level values are relatively low. One way of solving this problem is to introduce a correction to the one-factor noise index. This has been already done by taking into account the time variability (amplitude modulation) of the sound generated by wind turbines. Another proposal is to establish a multifactorial noise index which includes not only the noise parameters, but also non-acoustic characteristics (mainly visual), which are supposed to influence the overall perception of the annoyance associated with wind turbines. These two approaches will be discussed in this paper.