Chapter 7 page 1

The consulting network for Business, Environment and the Community they serve.

Wind Farms: The Potential for Annoyance

Dr Bob Thorne

Unreasonable Noise

Unreasonable noise is noise that intrudes upon the amenity of a person and due to its unpleasantness causes annoyance and distress. The mechanism for this transformation of sound to noise varies widely from person to person.

Annoyance

The World Health Organization[5] defines annoyance as "a feeling of displeasure associated with any agent or condition, known or believed by an individual or group to adversely affect them." Used as a general term to cover negative reactions to noise, it may include anger, dissatisfaction, helplessness, depression, anxiety, distraction, agitation or exhaustion.

The potential effects of wind farm noise on people are annoyance, anxiety, changing patterns of behaviour, and possibly sleep disturbance. The response of a person to noise from wind turbines is likely to depend on the following-

the variation in wind speed and strength;
the amount of time the receptor is exposed to the noise levels;
the nature of the noise output from the wind turbine including tonal content, modulation (blade swish) and or low frequency effects;
background noise levels at the receptor location;
wind and non-wind related effects;
non-acoustic factors, such as the sensitivity of the listener and attitude to the source.

There has been considerable research into noise annoyance from turbines, such as that reported by Pedersen and Persson Waye[3], identifying the relationship between noise from turbines and transportation. Figure 1 presents the relationship derived by Pedersen and Persson Waye showing the effect of “percent people highly annoyed” by noise from transportation and from wind turbines. Annoyance from wind turbine noise occurs at noise levels far lower than for traffic noise. The research by Pedersen and Persson Waye indicates that, for example, 10 percent of the exposed population is highly annoyed with traffic noise at 60 dB (A) DNL (day-night noise level) whereas the same degree of annoyance occurs at 36 dB(a) L_eq for a population exposed to wind turbine noise. Twenty percent of the population is highly annoyed with traffic noise at 68 dB(A) DNL whereas this same degree of annoyance occurs at 39 dB(a) L_eq for a population exposed to wind turbine noise...

previous table of contents next

Copyright of Papers and Intellectual Property of this document, and the physical devices or software described, belong to the respective authors or designers.