Adverse Health Effects of Industrial Wind Turbine Noise: How the Ear and Brain Process Infrasound

By Jerry Punch, PhD, and Richard James, INCE, BME

This article, the final of three installments, discusses the relationship between various health effects and our current understanding of the processing of infrasound by the ear and brain.^[1]

As noted in the second installment of this series, Dr. Geoff Leventhall, a co-author of the 2009 AWEA/CanWEA report, attributes the health complaints of people who live near industrial wind turbines (IWTs) to psychological stress, but does not acknowledge that IWTs can be detrimental to health because infrasound and low-frequency noise (ILFN) emitted by wind turbines are largely inaudible to humans. He stands on the argument, therefore, that what we can’t hear can’t hurt us.

We know that things we cannot see, touch, taste, or smell can hurt us, so why is it unreasonable also to believe that what we can’t hear might also hurt us?

Dr. Nina Pierpont, in describing Wind Turbine Syndrome (WTS), has expressed her belief that many of the symptoms comprising WTS are mediated by overstimulation of the vestibular system of the inner ear by ILFN. Recent evidence supports the general view that the functioning of both the vestibular and cochlear components of the inner ear, and their interconnections with the brain, mediate the type of symptoms that Pierpont and others have described.

Infrasound: More of a Problem Than We Thought?

Industrial-scale wind turbines generate peak sound pressure levels at infrasonic frequencies, especially between 0.25 and 3 Hz, as the blades pass in front of the tower. Most of us do not experience the energy in this lowest of low-frequency regions as sound; instead, we perceive a variety of other sensations. When present, infrasound can be more of a problem than audible sound.

Recent basic research on the inner ear conducted by Dr. Alec Salt and colleagues at the Washington University School of Medicine in St. Louis has provided a feasible and coherent explanation of how sound that is normally not audible can result in the kinds of negative reactions reported by people who are exposed to wind turbine noise. That research has shown that extremely low-frequency sound is largely inaudible to humans because the outer hair cells (OHCs) in the inner ear detect and effectively cancel it before it reaches the inner hair cells (IHCs). The IHC stereocilia, which do not contact the tectorial membrane, are fluid-coupled and sensitive to stimulus velocity, while the OHC stereocilia are sensitive to displacement. IHCs rapidly become less sensitive as stimulus frequency is lowered.

Cross-section of the cochlea (left), with illustration of IHCs and OHCs (right). Used by permission of Alec Salt, Washington University School of Medicine

Readers familiar with the anatomy of the ear know that approximately 95% of the fibers innervating the IHCs lead to the brain as afferent fibers, while only about 5% of the fibers innervating the OHCs are afferent fibers. Thus, we hear through our IHCs, and our hearing sensitivity is comparable to the calculated IHC sensitivity. The OHCs, which respond physiologically to infrasound, serve as a pathway for infrasound to reach the brain. Infrasonic signals that reach the brain are normally not perceived as sound, but are believed to stimulate centers other than auditory centers, resulting in perceptions that may be unfamiliar and disturbing.

Similar pathways to various centers of the brain also exist through the vestibular, or balance, mechanisms of the inner ear, meaning that it is biologically plausible for infrasound to produce the variety of sensations described by Pierpont, sensations such as pulsation, annoyance, stress, panic, ear pressure or fullness, unsteadiness, vertigo, nausea, tinnitus, general discomfort, memory loss, and disturbed sleep.

Salt and colleagues have also found that when higher-pitched sounds (150-1500 Hz) are present, they can suppress infrasound. This means that the ear is most sensitive to infrasound when higher-frequency sounds are absent. This occurs at night when wind turbine noise is present, ambient sound levels are low, and higher-pitched sounds are attenuated by walls and other physical structures.

Another relatively recent discovery is that there is likely a cause-effect relationship between AHEs and ILFN that mirrors that occurring in motion sickness. An experiment in the late 1980s, conducted using training-mission scenarios with Navy pilots, showed that motion sickness was associated with significant amounts of acoustic energy inside the flight cabin over the frequency range from just under 1 Hz to as low as 0.05 Hz (the nauseogenic range). Maximum sensitivity occurred at approximately 0.2 Hz. That experiment resulted in the conclusion that flight simulator sickness may be, to a significant extent, a function of exposure to infrasonic frequencies. This phenomenon is akin to seasickness, except that the acoustic energy causes nausea without body movement or visual stimulation.

As utility-scale wind turbines increase in size and power, the blade-pass frequency goes increasingly deeper into the nauseogenic zone.

Dr. Paul Schomer, nationally and internationally known for his work in acoustics and acoustic-standards development, has suggested that because the Navy test subjects responded to acoustical/vibratory energy with symptoms similar to motion sickness, many of the similar symptoms reported by people living near IWTs can be explained by exposure to infrasound from wind turbines at frequencies similar to those observed in the Navy’s test environment. Persons affected by wind turbine noise appear to be responding directly to acoustic stimulation of the same nerves and organs affected in that experimental environment.

Data Supports Reported Symptoms as Biologically Plausible
These research efforts of Salt and colleagues, Schomer, and others are leading the way in establishing the biological plausibility of the harmful effects of ILFN generated by wind turbines.

Dr. Salt dismisses the common perception that what we can’t hear can’t hurt us and has stated unequivocally that “Wind turbines can be hazardous to human health.”

Decisions regarding the siting of industrial wind turbines deserve careful attention to limiting noise exposure levels in community residents through specified restrictions on either distance or noise levels, or both. The right of the public to enjoy health and well-being should be paramount to the economic and political interests of the wind industry and governmental bodies. These rights need to be protected on a proactive, and not just on a retroactive, basis. Industrial-scale wind turbines should be sited only at distances from residents that are sufficient to minimize sleep disturbance and that do not put them at risk for a variety of other serious health problems.

Footnotes

1. Part 1: Adverse Health Effects of Industrial Wind Turbines; Part 2: Evidence of Negative Health Effects from Industrial Wind Turbines↵

Don’t Buy the Hype: Wind Turbines Do Not Impact Human Health

By Gabe Elsner

Editor’s Note: Today’s post, by Gabe Elsner, is in response to the 3-part series on the Adverse Health Effects of Wind Turbines, by Jerry Punch, Ph.D. & Richard James, INCE, BME. Mr. Elsner was invited to share his opposing views on the controversial subject of the health impact from industrial wind turbines.[1]

Opponents of wind farms have worked to stop the development of wind energy by claiming that it negatively impacts human health. However, courts across the globe have dismissed claims that wind turbines harm human health, repeatedly finding that there is no reliable evidence showing wind farms make people sick. The supposed evidence cited by Jerry Punch and Richard James fails to prove anything, and instead relies on flawed analysis by anti-wind campaigners claiming to be health experts.

In addition, governments in Canada, Australia, and the United States concluded in separate studies that wind turbines do not cause negative human health impacts.

A report released by the Energy and Policy Institute documents how health impacts claims by wind energy opponents have been soundly rejected in court. We studied court cases related to wind farms and health in the United States, Canada, Australia, the British Isles, and New Zealand. Out of the 49 cases that considered claims that wind turbines cause health impacts, courts dismissed 48 as lacking reliable evidence. Since 1998, 48 court rulings in five countries concluded that wind farms pose no threat to human health. The sole outlier is an instructive but unique case in which a turbine had a malfunction when originally installed, causing it to be noisier than usual. The judge in the Falmouth Wind Farm Case accepted medical claims by the complainants at face value, but there is no documentation that any medical experts were brought in as witnesses in the case to corroborate the claims.

Evidence Overwhelmingly Points Against Claims

Governments in Australia, Canada, and the United States studied peer-reviewed scientific research and also concluded that wind farms to do not cause negative impacts to human health. The Australian National Health and Medical Research Council stated, “There are no direct pathological effects from wind farms and that any potential impact on humans can be minimised [sic] by following existing planning guidelines.” The Ontario Chief Medical Officer of Health in Canada reported, “the scientific evidence available to date does not demonstrate a direct causal link between wind turbine noise and adverse health effects.” And finally, the Massachusetts Department of Environmental Protection concluded, “There is no evidence for a set of health effects, from exposure to wind turbines, that could be characterized as “Wind Turbine Syndrome” and also stated (among other conclusions), “strongest epidemiological study suggests that there is not an association between noise from wind turbines and measures of psychological distress or mental health problems.”

Put simply, governments around the globe have concluded in comprehensive reviews of peer-reviewed research: wind turbines do not cause human health impacts.

Finally, Punch and James cite inexpert “experts” and flawed anecdotal research to claim that wind turbines do cause negative impacts to human health. Over the past several years, anti-wind campaigners without credentials or relevant experience have attempted to serve as expert witnesses in civil suits, Environmental Review Tribunals (ERT) in Canada, and Environmental Resources and Development (ERD) proceedings in Australia.^[2]

In total, E&PI has documented that 16 frequently-cited anti-wind campaigners and their testimony were dismissed by courts due to lack of relevant expertise.

Questionable ‘Expert’ Claims

Nina Pierpont self-published a book, coining the phrase “Wind Turbine Syndrome.” Since then, 22 literature reviews on wind turbine health and many point-specific studies on wind turbine noise, vibration, infrasound, and shadow flicker, conducted by public health doctors and scientists, acousticians, epidemiologists, and related specialists considered Pierpont’s book along with other published literature. In every case, they found that her work was lacking in credibility. Recent major reviews have been conducted in Ontario, Massachusetts, Oregon, and Australia with the same results. In a 2013 wind farm hearing in Ontario, her book and testimony was dismissed for lack of expertise in the areas of “brain and ear physiology and pathophysiology, population-level studies in free-living organisms and medical interviewing.”

Dr. Carl Phillips is also presented as an expert witness at wind development planning hearings, but prior to performing anti-wind work he was a fixture in courtrooms related to tobacco health suits. Following his academic career, Phillips then set up his own research foundation and has attempted to counter peer-reviewed research, specifically regarding wind turbines. In a late 2013 court case related to the Bull Creek Wind Project, Phillips was dismissed because he “provided little rationale for his predictions,” “his conclusions were not based upon any particular adverse event reports,” and “the data he looked at was not organized in a systematic way and he did not break down the data to determine a dose-response relationship between wind turbine operation and the symptoms he described.”

Don’t Buy Into the Hype

In conclusion, Punch and James have made unsubstantiated claims and have not provided unbiased evidence from legitimate experts. Meanwhile courts and governments in countries around the world have concluded that wind farms do not harm human health. In courtrooms and in comprehensive, peer-reviewed studies, governments and courts have rejected the claims made by anti-wind campaigners. Punch & James’ recent series, Adverse Health Effects of Industrial Wind Turbines, is unsubstantiated and not supported by credible evidence or scientific research, and their continued efforts to attack wind energy should be properly labeled anti-wind propaganda.

Footnotes

1. Punch & James provide their response to Mr. Elsner’s claims in the comments below↵
2. See: Energy & Policy Institute↵

As Use of Wind Power Grows, So Do Fears that Turbines May Be Hazardous to Your Ears

By David Kirkwood

There is no more fiercely disputed topic these days than what source of energy we should draw on to power our ever-more power-consuming world. Words and phrases like greenhouse gases, war on coal, Solyndra, Keystone pipeline, fracking, Fukushima Daiichi and Chernobyl, energy independence, rising sea level, global warming and scientific conspiracy are invoked to defend or attack pretty much every energy source known to man.

So, is it any wonder that wind power, one of the fastest-growing alternatives to fossil fuels, is also stirring controversy?

True, it doesn’t pollute the air or water or add heat to the atmosphere. And, unlike burning coal, gas, and oil, using wind power cannot deplete earth’s supply of wind.

As major wind farms are being erected on land and off-shore, wind power is becoming more economically viable in many countries, including the U.S., Canada, Germany, and, above all, Denmark. There, over 40% of the nation’s electrical power is being generated from renewable sources—primarily wind.
 

HEALTH PROBLEMS REPORTED

Nevertheless, wind power is not without its problems and critics. One issue is the damage that, some scientists believe, giant wind turbines, up to 500 feet in height, can cause to the auditory systems of people who live too close.

Last month on the blog Hearing Views, Jerry Punch, PhD, an audiologist, and Richard James, an acoustical consultant, published a compelling three-part series discussing how the sound generated by wind turbines—even sound that is too low in frequency for human beings to hear–may be causing the negative reactions reported by people residing close to wind turbines. These include sleep disturbance, headache, dizziness, tinnitus, ear pressure or pain, irritability, and fatigue.
 

HEALTH CANADA WEIGHS IN

The latest word in the wind power debate comes from Health Canada, which, according to its web site, is “the Federal department responsible for helping Canadians maintain and improve their health, while respecting individual choices and circumstance.”

It published a report, “Wind Turbine Noise and Health Study: Summary of Results,” on October 30 presenting the findings from a large-scale epidemiology study on some 1200 families in the provinces of Ontario and Prince Edward Island. Most of the people who participated lived within 600 meters of a wind turbine.

The purpose of the study, launched in July 2012, was “to support a broader evidence base on which to provide federal advice and in acknowledgement of the community health concerns expressed in relation to wind turbines.”

And, what did the study find about the effects of wind turbines? It’s not entirely clear. Interestingly, when the Canadian Broadcasting System (CBC), reported on the study, it headlined its story “Wind turbine noise not linked to health problems, Health Canada finds.”

Indeed, in its report’s Preliminary Research Findings,” Health Canada stated:

“Exposure to WTN was not found to be be associated with any significant changes in reported quality of life for any of the four domains [Self-reported Sleep, Self-reported Illnesses and Chronic Diseases, Self-reported Stress, and Quality of Life], nor with overall quality of life and satisfaction with health.”

However, the Health Canada report also noted that a number of effects are statistically associated with exposure to increasing levels of WTN. These effects included “annoyance towards several wind turbine features (i.e., noise, shadow flicker, blinking lights, vibrations, and visual impacts).”

Health Canada pointed out that annoyance with noise from wind turbines was “statistically related to several self-reported health effects including, blood pressure, migraines, tinnitus, dizziness, scores on the PSQI [Pittsburgh Sleep Quality Index], and perceived stress.”
 

MORE TO COME

There is no consensus yet on the damaging effects that wind turbines may have on the ears and other organs of people living nearby. What is clear is that the topic will continue to be studied and debated. On December 10, Hearing Views published a rejoinder by Gabe Elsner from the Energy & Policy Institute to the series by Punch and James discussing the dangers of wind power.

Ideally, the outcome of all the research and debate will be to find a safe, non-annoying, and economically viable way to reap the benefits of wind power.

Adverse Health Effects from Industrial Wind Turbines

By Jerry Punch, PhD, and Richard James, INCE, BME

This post, the first of a three-part series, provides a broad overview of the topic. The second installment will review the major research findings linking low-frequency noise and infrasound from industrial wind turbines with effects on health and quality of life. Part three will discuss the relationship between various health effects and the processing of infrasound by the ear and brain.^[1]

Cary Shineldecker was skeptical about the wind project the Mason County, Michigan, planning commission was considering for approval. His home, two miles from Lake Michigan, was located in an area where nighttime noise levels were around 25 dBA, with only occasional traffic and seasonal farmland noises. The rolling hills, woodlots, orchards, fields, and meadows surrounding his property contributed to its peaceful country setting. He voiced his skepticism about the wind turbines repeatedly in community meetings held before Consumers Energy was finally granted approval to construct 56 476-foot turbines, one that would be 1,139 feet from his property line, six within 3,000 feet, and 26 close enough to be visible from his property.

Cary and his wife, Karen, started to suffer symptoms of ear pressure, severe headaches, anxiety, irritability, sleep disturbance, memory loss, fatigue, and depression immediately after the turbines began operating.

An industrial-scale wind turbine during installation near the Shineldecker home in Mason County, Michigan.

Gradually, as sleep disturbance turned into sleep deprivation, they felt their home was being transformed from a sanctuary to a prison. Deciding to sell their home of 20 years, they put it on the market in March 2011, and it has remained unsold for 3-1/2 years. For the past year and a half, their nightly ritual has been taking sleeping medications and retreating into their basement to try to sleep on a corner mattress.

The Shineldeckers received few offers to buy their home, and recently accepted an offer that would mean a substantial financial loss. They are scheduled to go to trial against Consumers Energy, and if their case goes to settlement without a trial, they will likely be forced into a confidentiality agreement about their case.

MANY SUCH COMPLAINTS

Similar complaints of adverse health effects (AHEs) associated with living near utility-scale wind turbines have become commonplace in the U.S. and other developed countries. Energy companies in the U.S., motivated by lucrative tax subsidies available for developing wind resources as a form of green energy, are pushing aggressively to install more wind turbines, typically locating them near residential properties. Many rural residents now have one or more industrial machines that stand over 40 stories tall on the property alongside their home. Complaints about noise from people living within the footprint of wind energy projects are very similar to those experienced by the Shineldeckers.
Those who have never visited a wind project or who visit one only during the daytime often leave believing that the complaints of noise are unfounded, and commonly assume them to be psychologically motivated or a form of NIMBYism ^[2]. Those living near wind turbines say that unless one is willing to spend several nights in the area they have not experienced the noise that causes the complaints.

The Changing Rural Landscape

Prior to the installation of the wind turbines, these rural communities were typically very quiet at night, with background sound levels ranging between 20 and 25 dBA. After the turbines began operation, the noise levels jumped to 40 or even 50 dBA, and sometimes higher. It is common for wind turbines to be barely audible during the day, yet be the dominant noise source at night. Environmental sounds are quieter in the evening, lowering the background sound levels, and wind speeds tend to be higher at blade height during nighttime hours, which increases sound emissions. Further, nighttime weather conditions enhance sound propagation. The result is that at night wind turbines can be a significantly more noticeable noise source than during the daytime.

Commercial wind turbine blades produce aerodynamic noise in both the inaudible and audible range, collectively referred to as infrasound and low-frequency noise (ILFN). Although some of the audible noise is above 200 Hz, much of it falls into the low-frequency region around 0-100 Hz. Infrasound, generally considered to be inaudible, encompasses sound energy in the range from 0-20 Hz. It is measureable with either an infrasonic microphone or a microbarometer. The frequency and amplitude of wind turbine noise depend mainly on the blade-rotation speed. Measurements show increased acoustic energy with decreasing frequency, reaching a maximum at frequencies under 1 Hz.

Promoters of wind energy frame it in agricultural terms that portray it as harvesting the wind. This framing leads to the belief that wind farms are a natural fit with agricultural land use.

From this viewpoint, farmers should also be allowed to use their land to harvest the energy of the atom by hosting a small nuclear plant. Hosting a utility-scale wind turbine is not farming; it is operation of a commercial utility. The installation of utility-scale, energy-conversion machines requires strict zoning and regulation, as one would expect for a zoned industrial region. These machines are in no way similar to traditional agricultural equipment. Thus we consider the term industrial to be an accurate description of utility-scale wind turbines.

Wind turbines are often sited in regions where agricultural land use is intermixed with residential land use. A single wind energy utility typically consists of 40 to 60 wind turbines. Forty-five 2-MWatt turbines cover about 36 square miles of land. This requires only 10 to 20 farmers to sign leases for hosting one or more of the turbines, but may put several hundred non-participating farms and residential homes within the risk zone for noise disturbance.

While a few farmers or landowners in the host community benefit financially, many others—often at ratios of 20 to 1 or higher—find that the peace and quiet of evenings and nights that attracted them to the rural community is replaced with the unwanted consequences of audible sounds and inaudible infrasound.

In the final two installments of this three-part series, our goal is to explain the bases for a variety of health complaints that are being associated with the current practice of locating industrial-scale wind turbines as close as 1,200 to 1,500 feet from homes. In areas with a relatively long history of industrial wind turbines (IWTs), a distance of at least 1-1/4 miles (2 kilometers)—and more in areas with hilly terrain—is now considered necessary to avoid negative impacts on health.

Footnotes

1. Interested readers may wish to refer to the article, “Wind-Turbine Noise: What Audiologists Should Know,” published in the July-August 2010 issue of Audiology Today, as a backdrop for this series↵
2. Not In My Back Yard: NIMBY↵

The Negative Health Impact of Noise from Industrial Wind Turbines: The Evidence

By Jerry Punch, PhD, and Richard James, INCE, BME

Evidence that industrial wind turbines (IWTs) negatively impact human health is vast and growing. Although that evidence acknowledges that the exact exposures needed to impact health and the percentage of the affected population are still unknown, there is indisputable evidence that adverse health effects (AHEs) occur for a non-trivial percentage of exposed populations. Here, we give an overview of that evidence. [2]

Wind turbine noise is not known to cause hearing loss. Interestingly, though, individuals who have hearing disorders may be more susceptible than persons with normal hearing to AHEs from wind turbine noise, and people who are deaf can suffer the same ill effects as those who have normal hearing when exposed to wind turbine noise. The latter finding supports the view that infrasound, not just the audible whooshing, low-frequency noise emitted by wind turbines, is the cause of many of the health complaints.

The anecdotal evidence, documented on internet blogs, in newspaper articles, in expert testimony in legal proceedings, and recently in the documentary movies Windfall and Wind Rush, is compelling and illustrative of the similarity in symptoms. These adverse symptoms appear when people are exposed to operating wind turbines, and disappear when the turbines stop operating. These observations resemble single-subject research experiments, in which individuals serve as their own controls while being subjected to alternating conditions or treatments. Dr. Carl Phillips, a noted epidemiologist, describes the use of adverse event reporting as a first step in establishing the existence, prevalence, and spread of a variety of health conditions, as well as adverse reactions to such agents as medications and environmental pollutants.

Reports that many families abandon their homes after IWTs begin operation make the anecdotal evidence particularly compelling.

Studies conducted in Denmark, the Netherlands, Germany, and Sweden, where residents have many decades of experience with IWTs, collectively indicate that wind turbine noise differs from and is more annoying than other sources of noise, including community, transportation, and industrial sources.

As the blade passes the tower, infrasound pulses are emitted, while more audible low-frequency sounds are produced by blade movement. Used by permission of Esther Wrightman, Ontario.

These differences are attributed to the substantial infrasound and low-frequency noise (ILFN) produced by the turbines. Such sounds are not easily masked by other environmental sounds, including wind noise.

Annoyance from turbine noise at 35 dBA corresponds to the annoyance reported for other common community-noise sources at 45 dBA. The World Health Organization (WHO) has concluded that observable effects of nighttime, outdoor noise levels of 40 dBA or higher will lead to diminished health. This also occurs when levels inside homes (especially bedrooms) rise above 30 dBA or contain non-steady and/or low-frequency noise.

Yet, the wind industry commonly promotes 50 dBA as an appropriate limit for homes, even though the World Health Organization has identified such high levels as a cause of serious health effects.^[3]

Health Effects of Wind Turbine Noise

Sleep disturbance is by far the most common complaint of families living near wind turbines. Prolonged lack of sleep affects our capacity to learn and negatively affects our memory, temperament, heart health, stress levels, and hormones that regulate growth, puberty and fertility. It can also lead to high blood pressure, changes in heart rate, and an increase in heart disease, as well as weight gain and lowered immunity to disease. These symptoms have regularly been reported by individuals who live near IWTs.

In a controlled clinical study, residents who lived within 1.4 kilometers, or 0.87 mile, of IWTs exhibited greater sleep disturbance and poorer mental health than those living at distances greater than 3.3 kilometers, or 2 miles, away, and scores on sleep and mental-health measures correlated well with noise exposure levels. Another study found lower quality of life (QoL) in residents living within 2 kilometers of a turbine installation than at longer distances. Abandonment of homes near wind turbines has been associated primarily with disruptions to sleep and QoL.

Nina Pierpont, MD, PhD^[4], a practicing pediatrician, coined the term Wind Turbine Syndrome(WTS) in 2009 to describe the symptoms she observed in a cohort study of 38 members of 10 families. Those symptoms include: sleep disturbance; headache; Visceral Vibratory Vestibular Disturbance (VVVD); dizziness, vertigo, unsteadiness; tinnitus; ear pressure or pain; external auditory canal sensation; memory and concentration deficits; irritability and anger; and fatigue and loss of motivation. Although her case-series report, published as a book, has often been maligned by the wind industry as being non-scientific, an increasing body of scientific evidence supports her observations and their links to exposure to wind turbines. Dr. Robert McMurtry, a well-respected Ontario physician, recently proposed specific diagnostic criteria for a case definition of AHEs due to IWTs.

Industry Reacts to Claims

In 2009, a joint report of the American and Canadian Wind Energy Associations (AWEA/CanWEA) established the basis for arguments routinely used by wind energy advocates to persuade the public and public officials that IWTs present no health risks. The panel members who produced the report were handpicked by AWEA’s acoustical consultant, and all had prior positions on noise from wind turbines favorable to the industry.

The report concluded that exposure to wind turbine noise has no direct adverse physiological or health consequences, a conclusion shown to be erroneous by multiple lines of evidence, at least several of which were established prior to the report. The report’s major weaknesses were its comparisons of wind turbine noise levels to those produced by other environmental noises and its embrace of the A-weighted measurement scale as valid, even though that scale minimizes low-frequency sound and completely excludes infrasound.

Several scholarly researchers have rejected the AWEA/CanWEA report as misleading and unscientific. One of the report’s co-authors, Dr. Geoff Leventhall, whose own research demonstrates that ILFN leads to various health symptoms, attributes those symptoms to extreme psychological stress from low-frequency noise, but does not acknowledge that IWTs also cause such symptoms. He argues that the ILFN emitted by wind turbines falls below the threshold of hearing, claiming that what we can’t hear can’t hurt us—a topic we will address in our final installment.

Footnotes

1. Part 1: Adverse Health Effects of Industrial Wind Turbines; Part 3: Adverse Health Effects of Industrial Wind Turbines: How the Brain & Ear Process Infrasound↵
2. Of note: the authors of this series are currently preparing a comprehensive, fully referenced paper for publication elsewhere↵
3. Night Noise Guidelines for Europe set limit at 40 dBA↵
4. MD degree earned from Johns Hopkins and PhD from Princeton↵