Wind Noise: A Continuing Issue (Night Amplification)
By Sherri Lange — September 13, 2021
Wind turbine “noise” [grinding and thumping and vibration aside], swoosh and/or amplitude modulation is accelerated by up to five times at night; Flinders University finds.
Likely more annoying than other sources of noise at the same level, the study finds.
Australia has commissioned a five-year study of the effect of noise from industrial wind turbines on the local residents. The rare investigation can only be bad news for the PR-propped industry, given the image of turbines being noiseless and in a field of green (mute and photoshopping at work).
In Renew Economy, Sophie Vorrath reported the latest:
New federally funded research investigating the association of wind farm noise with adverse effects on humans has found that the “swoosh” sound made by spinning turbine blades was likely to be more noticeable – and more annoying – to nearby residents during the night than during the day.
The research, led by Flinders University PhD candidate Duc Phuc Nguyen and acoustic expert Dr Kristy Hansen, has combined long-term monitoring of wind farm noise with machine learning to quantify and characterize the noise produced by wind turbines.
The resulting two new publications mark the latest findings in the five-year Wind Farm Noise study that was funded by the federal government’s National Health and Medical Research Council, with funding also supplied through Australian Research Council grants.
One of the study co-authors made this analogy (quoted by Vorrath):
So like if you’re in a hotel, a very cheap hotel, and there’s a noisy refrigerator in there and it’s humming and then not only is that noise annoying because it’s a hum, but then imagine if someone starts switching it on and off every second.
Background
Dr. Christopher Hanning, a now-retired Consultant in Sleep Disorders Medicine to the University Hospitals of Leicester NHS Trust, writes:
In the short term … deprivation of sleep results in daytime fatigue and sleepiness, poor concentration and memory function. Accident risks increase. In the longer term, sleep deprivation is linked to depression, weight gain, diabetes, high blood pressure and heart disease.
I do not pretend to be an expert in the effects of noise, but I do know that in over 30 years as a GP I have seen countless patients presenting with the effects of insomnia, and shift workers in particular suffer far more than the general population with the effects of disturbed sleep. What I find astonishing is that the noise regulations for the wind industry permit MORE noise to be generated by the turbines at night than during the day. This is completely contrary to noise pollution legislation, World Health Organisation (WHO) guidelines – and common sense.
It is well known and accepted worldwide that residents near wind turbines face special challenges, not the least being loss of restorative sleep. Master Resource has reported on the work of acoustician Steven Cooper, already known as an expert in “amplitude modulation,” or as he calls it, “modulation of the amplitude” (here).
Cooper’s precision reflects his insight that sensitive people can identify inaudible “noise” as a sensation. In his words:
My work has questioned/examined what our general acoustic analysis provides and the errors in such analysis; threshold of hearing and threshold of sensation; the challenges in creating that sound; subjective assessment of mono vs. stereo; and the infrasound sound of wind turbines versus the pulsation of the wind turbine sound that is occurring at an infrasound rate.
I have also done a case study that showed sensitive people can identify the presence of an inaudible wind turbine noise, putting the Kelley Mod-1 work (in the 1908s) with the work on fluctuation from Zwicker and Fastl, clarifying the incorrect use of Amplitude Modulation in relation to wind turbine noise, and with the assistance of a psychologist in a single case study, showing the response of the inaudible pulsating wind turbine noise was centered in the frontal lobes of the brain.
Growing Evidence …
The recent Flinders University study on “swoosh” and “amplitude modulation,” “Long-term quantification and characterisation of wind farm noise amplitude modulation,” confirms the work of Cooper and also the reports and work of highly respected Dr. Nina Pierpont. She is a frontrunner to exploring personal accounts of loss of health and amenity from proximity to wind turbines in her book: Wind Turbine Syndrome. A Report on A Natural Experiment. The attempts to discredit Dr. Pierpont are epic, and recorded in several countries. The international pushback, such as from Senator John Madigan of Australia, mirrors a heroic story, a voyage to protect people from obvious harm.
Please see this video of about 20 minutes from Dr. Pierpont’s webpages: the story of the Shineldecker family of Michigan. Unforgettable, tragic. Home life “pulverized” according to the editor of the website. (The video describes the violations of land and social contract responsibility: Mr. Shineldecker at about 16 minutes describes his family’s loss of health and amenity.)
In this video, Mr. Shineldecker (an engineer) painstakingly and courteously explains to the wind developer, an outfit named Consumers Energy, how it systematically violated and ultimately pulverized his family’s home and life.
This anecdotal report, and sadly, so many more, thousands more, can be seen as deeply relevant to the Flinders University findings. Indeed, the findings of the impacts, increased nighttime impacts of even ONE audible component, the “swoosh,” and felt up to FIVE TIMES more often than daytime, AM (Amplitude Modulation), confirms again that the impacts are not in victims’ heads. See our previous post here.
See also the testimony of Dr. Sandy Reider, speaking to the VT Public Service Board, 2014.
In the interest of full disclosure, I am not being paid for involvement in this issue, nor did I seek this out; rather, it found me by way of a patient I had known well for several years, and who, in late 2011, suddenly developed severe insomnia, anxiety, headaches, ringing ears, difficulty concentrating, and frequent nausea, seemingly out of the blue. This puzzled us both for a few months before we finally came to understand that he suffered from what was, then, a relatively new clinical entity known as “wind turbine syndrome”, related in his particular case to the comparatively small NPS 100 KW turbine that began generating power atop Burke Mountain in the fall of 2011.
In the course of the 2012 legislative session, I described this patient in detail in testimony for the Senate Natural Resources and Health Care Committees, as well as the Governor’s Siting Commission. Since his symptoms were so typical and similar to those described by thousands of other individuals living too close to large wind turbines all over the globe, I have attached my testimony for the Senate Health Care Committee and encourage you to review it for its very characteristic description of what it is that this board, I trust, hopes to mitigate by recommending more protective sound standards for these industrial wind installations.
Conclusion
Adding the night hours when wind is most active, including the SWOOSH together with vibration, infrasound and low frequency noise, various grinding of gears, whining, and whirring, depending on speed of wind, direction, landscape and so on, and you may get an unforgettable night of despair.
As F. Scott Fitzgerald noted: “The worst thing in the world is to sleep and not to.”
Appendix: Long-term quantification and characterisation of wind farm noise amplitude modulation. — Flinders University
With wind generation one of the fastest-growing renewable energy sectors in the world, Flinders University experts are using machine learning and other signal processing techniques to characterise annoying noise features from wind farms.
Two new publications from the ongoing Wind Farm Noise Study take another step towards improving wind turbine noise assessment methods, guidelines and wind turbine design to make wind energy more acceptable to surrounding communities.
The new studies find that night-time ‘swoosh’ sound — technical (sic) referred to as ‘amplitude modulation’ (AM) — from wind turbines is likely to be heard by neighbouring residents up to five times more often than during day-light hours, depending on wind direction, season and wind farm distance.
For the first time, the research led by Flinders University PhD candidate Duc Phuc (‘Phuc’) Nguyen and acoustic expert Dr Kristy Hansen has combined long-term monitoring of wind farm noise with machine learning and available knowledge to quantify and characterise AM in wind turbine noise.
“We found that the amount of amplitude modulation present during the daytime versus night-time varies substantially occurring two to five times more often during the night-time compared to the daytime,” says Mr Nguyen.
“The noise seems to worsen after sunset when amplitude modulation can be detected for up to 60% of the night-time at distances around 1 km from a wind farm.
“At greater than 3 km, amplitude modulation also occurs for up to 30% of the night-time.”
The Wind Farm Noise Study, based at the Adelaide Institute for Sleep health at Flinders University, is investigating noise characteristics and sleep disturbances at residences located near wind farms. The association between wind turbine noise and adverse effects on humans is an ongoing debate.
Dr Hansen says the directional nature of wind turbine noise means residents living in downwind and crosswind conditions are likely to be more disturbed by wind turbines.
“We found that AM occurs most often during these wind directions,” she says. “Using these recent advances in machine learning, we have been able to develop an AM detection method that has a predictive power close to the practical limit set by a human listener.”
“This includes the noise that increases and decreases as the blades rotate, or AM, including a ‘swoosh’ sound, which further contributes to the negative effects of wind turbine noise.
“These studies advance our ability to measure and monitor the noise from wind turbines that is likely to be more annoying that other noise types at the same level.”
Journal References:
- Phuc D. Nguyen, Kristy L. Hansen, Bastien Lechat, Peter Catcheside, Branko Zajamsek, Colin H. Hansen. Benchmark characterisation and automated detection of wind farm noise amplitude modulation. Applied Acoustics, 2021; 183: 108286 DOI:10.1016/j.apacoust.2021.108286
- Phuc D. Nguyen, Kristy L. Hansen, Peter Catcheside, Colin H. Hansen, Branko Zajamsek. Long-term quantification and characterisation of wind farm noise amplitude modulation. Measurement, 2021; 182: 109678 DOI:10.1016/j.measurement.2021.109678
[Originally published at Master Resource.]