Sound Level Resources

Click on the links below to download PDF files.

People ask about the level of sound coming from wind turbines. We have researched this subject and we provide below a collection of articles published on it:

Article #1: Low Frequency Noise and InfraSound from Wind Turbine Generators - A Literature Review

Article #2: Is Low Frequency Noise a Problem for Wind Turbines?

Article #3: Wind Turbine Noise Issues

Article #4: Noise Quantification and Monitoring: An Overview

Article #5: Noise Annoyance from Wind Turbines

Article #6: Facts About Wind Energy & Noise

Article #7: Article on wind turbine low frequency noise from the American Wind Energy Association.

Article #8: Sound from Wind Turbines

Article #9: Leventhall Report on Low Frequency Noise

Article #10:Power Point Presentation by University of Massachusetts

The article below is a reprint from "Wind Power Monthly", October 2005

"Low Frequency Noise ( or Infrasound ) has resurfaced as an issue for UK wind power after anti-wind farm pressure group the Renewable Energy Foundation distorted the finding from a study by Keele University into the effect of wind turbines at Dunlaw on the Eskdalemuir seismic array in the Scottish Borders. REF is questioning the risk to human health from wind farms and quotes from the study: When the wind farm starts to generate (even) at low wind speeds, considerable infrasound signals can be detected at all stations out to circa 10 kilometers. REFs concerns have been picked up by the Scottish press. But Peter Styles, a professor, and Sam Toon, who led the Keele University research, refute the misconceptions arising from REFs interpretation of their findings. They complain to the Scotsman newspaper that "to give the impression that vibrations can be felt at a distance of ten kilometers is highly misleading". They continue: "The level of vibration from wind turbines is so small that only the most sophisticated instrumentation and data processing can reveal their presence and they are almost impossible to detect," adding: "This is at levels far below that at which humans will detect the low frequency sound. There is no scientific evidence to suggest that infrasound has an impact on human health."

Dr Geoff Leventhall on Low Frequency Noise and Wind Turbines (04-Jun-04):

Dr Geoff Leventhall is an independent UK consultant in noise vibration and acoustics and, in this role, he was asked by Genesis to prepare a report, as part of the Genesis submission for the Awhitu wind farm, looking at the connection between low frequency noise and wind turbines. If you are interested in finding out about the facts concerning wind farms and their sound emissions you should read the whole report (a link on the above list).

If you do not have time for this then consider the following from page 6 of the report;

- It detracts from those people who have genuine low frequency noise problems, often from industrial exhaust fans, compressors and similar.

"When a group of residents decides to object to a development, they often support each other with strong emotions, which can sometimes lead them astray. The emphasis on low frequency noise is an example of this. Over the past 30 years there has been a great deal of confusion and misinformation about low frequency noise, mainly in the popular media. Much of it can best be described as "hot air" but complainants uncritical acceptance of what they read in unreliable sources has two unfortunate effects.

- It undermines the credibility of the complainants, who may be harming their own cause in their apparent grasping at straws approach".

The summary of the report is as follows;

"The rational study of low frequency noise, its effects and criteria for control, has been bedeviled by exaggerations, half truths and misrepresentations, much of its fomented by media stories over the last 35 years. The result in the UK and it is probably similar in other countries, is that an incorrect concept "low frequency noise is a hazard" has taken root in the national psyche, where it lies dormant waiting for a trigger to arouse it. The current trigger is wind turbines. Previous ones have been gas pipelines and defense establishments. When this is coupled to the failing, which we all have, of generally believing what we want to believe, it is seen that it is not easy to persuade lay people of the truths of low frequency noise which can be summarized as;

- High levels of low frequency noise are required for perception, increasing as the frequency reduces.

- The ear is the most sensitive receptor in the body. If you cannot hear it you cannot feel it.

- Continuous audible low frequency noise can be a nuisance, as can any other noise, but it must be above threshold for this to occur.

- Where problems often arise with predominantly low frequency noise, this is because the A-weighted assessment methods do not cater for it. This leads to the noises being dismissed as not a nuisance, leaving unhappy complainants in a distressed state.

"However the above must be considered in light of the very low levels of low frequency noise from wind turbines".