Resource Documents: Noise (572 items)
Documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are provided to assist anyone wishing to research the issue of industrial wind power and the impacts of its development. The information should be evaluated by each reader to come to their own conclusions about the many areas of debate.
Author: Gwak, Doo Young; et al.
Wind turbine noise is considered to be easily detectable and highly annoying at relatively lower sound levels than other noise sources. Many previous studies attributed this characteristic to amplitude modulation. However, it is unclear whether amplitude modulation is the main cause of these properties of wind turbine noise. Therefore, the aim of the current study is to identify the relationship between amplitude modulation and these two properties of wind turbine noise. For this investigation, two experiments were conducted. In the first experiment, 12 participants determined the detection thresholds of six target sounds in the presence of background noise. In the second experiment, 12 participants matched the loudness of modified sounds without amplitude modulation to that of target sounds with amplitude modulation. The results showed that the detection threshold was lowered as the modulation depth increased; additionally, sounds with amplitude modulation had higher subjective loudness than those without amplitude modulation.
Kiseop Yoon, Doo Young Gwak, Yeolwan Seong, Seunghoon Lee, Jiyoung Hong, and Soogab Lee
Journal of Mechanical Science and Technology
October 2016, Volume 30, Issue 10, pp 4503–4509
Kiseop Yoon is a Ph.D. student in the Department of Mechanical and Aerospace Engineering at Seoul National University. He received his B.S. degree from the School of Mechanical and Aerospace Engineering at Seoul National University in 2011. His research interests are in the area of active noise control system and the perception of environmental noise.
Doo Young Gwak is a Ph.D. student in the Department of Mechanical and Aerospace Engineering at Seoul National University. He received his B.S. degree from the School of Mechanical and Aerospace Engineering at Seoul National University in 2010. His research interests are in the area of psychoacoustics and the prediction of ‘drone’ noise.
Yeolwan Seong is a Researcher in the Defense Agency for Technology and Quality at Daejeon. He received his M.S. degree from the School of Mechanical and Aerospace Engineering at Seoul National University in 2013. His research interests are in the area of psychoacoustics and railway noise.
Seunghoon Lee is a Researcher in the Korea Aerospace Research Institute at Daejeon. He received his Ph.D. degree from the School of Mechanical and Aerospace Engineering at Seoul National University in 2014. His research interests are in the area of helicopter aerodynamics and wind turbine noise.
Jiyoung Hong is a Researcher in the Korea Railroad Research Institute at Uiwang. She received her Ph.D. degree from the School of Mechanical and Aerospace Engineering at Seoul National University in 2011. Her research interests are in the area of human noise perception and environmental noise impact assessment.
Soogab Lee is a Professor in the Department of Mechanical and Aerospace Engineering at Seoul National University. He received his Ph.D. in Aeronautics and Astronautics from Stanford University in 1992. He worked as a Research Scientist at NASA Ames Research Center from 1992 to 1995. His research interests are in the area of aerodynamics and acoustics of rotating machines including wind turbine systems.
Author: Smith, Michael; Ögren, Mikael; Thorsson, Pontus; Pedersen, Eja; and Persson Waye, Kerstin
In accordance with the EU energy policy, wind turbines are becoming increasingly widespread throughout Europe, and this trend is expected to continue globally. More people will consequently live close to wind turbines in the future, and hence may be exposed to wind farm noise. Of particular concern is the potential for nocturnal noise to contribute towards sleep disturbance of nearby residents. To examine the issue, we are implementing a project titled Wind Turbine Noise Effects on Sleep (WiTNES). In a pilot study described in this paper, we performed an initial investigation into the particular acoustical characteristics of wind turbine noise that might have the potential to disturb sleep. Six young, healthy individuals spent 5 nights in our sound exposure laboratory. During the final 3 nights of the study, the participants were exposed to wind turbine noise, which was synthesised based on analysis of field measurements. Exposures involved periods of different amplitude modulation strengths, the presence or absence of beats, different blade rotational periods, and outdoor LAEq,8h=45 or 50 dB with indoor levels based on the windows being fully closed or slightly open. Physiological measurements indicate that nights with low frequency band amplitude modulation and LAEq,8h=45 dB, slightly open window (LAEq,8h=33 dB indoors) impacted sleep the most. The presence of beats and strong amplitude modulation contributed to sleep disturbance, reflected by more electrophysiological awakenings, increased light sleep and wakefulness, and reduced REM and deep sleep. The impact on sleep by these acoustic characteristics is currently the focus of interest in ongoing studies.
Michael G. Smith, Mikael Ögren, Pontus Thorsson, Eja Pedersen, and Kerstin Persson Waye
University of Gothenburg, Sweden (MGS, MÖ, KPW).
Chalmers University of Technology Sweden (PT).
Lund University, Sweden (EP).
Presented at the 22nd International Congress on Acoustics, Buenos Aires, 5–9 September 2016
Author: WSP Parsons Brinckerhoff
This review was commissioned by the Department of Energy & Climate Change (DECC) in spring 2015 and finalised before DECC became part of the Department for Business, Energy and Industrial Strategy in July 2016.
The research has reviewed the evidence on the response to amplitude modulation (AM) in relation to wind turbines. It was undertaken by a research team lead by WSP Parsons Brinkerhoff, who are responsible for the overall editorial content of the report, and supported by three independent external reviewers.
The review considered the robustness of relevant dose-response relationships and how, in a policy context, the level(s) of AM in a sample of noise data should be interpreted. In particular, it considered at what point AM causes a significant adverse impact and has recommended how excessive AM from wind turbines might be controlled through the use of an appropriate planning condition.
The final report addresses comments raised by three peer reviewers, appointed by DECC. The reviewers, from Denmark and the Netherlands, are experts in noise and health.
While this research does not represent planning guidance, BEIS encourages developers and planning authorities in England to consider this research when determining if an AM condition would be appropriate.
The contractor worked closely with the Institute of Acoustics’ AM working group, who in August 2016 recommended a preferred metric and methodology for quantifying and assessing the level of AM in a sample of wind turbine noise data [click here for review from the Independent Noise Working Group].
Author: Palmer, William
Introduction. A common regulatory acceptance criterion for wind turbine installation in Canada is that sound pressure level does not exceed 40 dBA outside a home when the wind speed at 10 metres elevation does not exceed 4 metres per second. A clue to the ineffectiveness of this criterion can be seen from over 2700 complaints filed in Ontario with regulators by residents living in homes where acoustic conditions were predicted in approved models to comply with the current criterion. Residents noted the intrusiveness of an imposed sound higher in amplitude and different in quality than the pre-existing background. Residents reported disrupted sleep, and adverse health consequences. Fundamental premises of Environmental Protection Acts (EPA) are that emissions of a contaminant such as noise should not cause an adverse effect including loss of enjoyment of normal use of property, or annoyance that lead to human health impacts. …
Discussion. The subject of amplitude modulation of wind turbine noise emissions (otherwise described as a cyclical noise rising and falling in magnitude) has been a principal focus of wind turbine noise international conferences in Glasgow (2015) and Denver (2013). Monitoring of the sound inside homes displays a different character than outside, showing pulses with peak to trough amplitudes exceeding 5 dB at frequencies that are within the audible range. A simple example shows that dBA weighting does not adequately reflect perception and annoyance. White noise at 40dBA has a very different perception than pink noise at 40 dBA.
William K.G. Palmer, TRI-LEA-EM, Paisley, Ontario
Canadian Acoustics – Acoustique canadienne Vol. 44 No. 3 (2016) – pp. 42-43