The respondents

In april 2007 the questionnaires were send by the section Applied Research at the University Medical Center Groningen. Ultimately 725 of the 1948 adult residents completed and returned the questionnaire. They are referred to as the respondents.

To make sure the respondents were not predominantly residents that were annoyed by wind turbine sound, a random selection was performed on non-respondents. No statistical significant differences in annoyance were found between the respondents and non-respondents. This showed that the respondents were similar to the non-respondents.