I wrote two surprisingly popular articles on wind turbine infrasound noise in summer of 2019, that I have now combined into one edited, reformatted article that will be much easier to read on phones ... hopefully with more woids spelled wright dis time:
As an audiophile since 1965, who has built many do-it-yourself subwoofers since the 1980's, I have always been interested in bass frequencies and infrasound. So interested, that in my first year of engineering school, at the Rochester Institute of Technology, the only thing I can still remember today is our infamous "speaker experiment". One budding engineer had a pair of huge homemade speakers with 15" bass drivers, whose bass was extended with "tuned ports", considered state of the art audio at the time (1971).
Listening to rock music in a small dorm room, sitting on the side of a bed with the speakers on both sides of the bed, woofers aimed at the sides of our chest, we found that certain frequencies of bass caused our chest cavities to resonate. So we borrowed a tone generator, and did "scientific" experiments, fueled by excessive beer, with coeds as some of our subjects. We found out that chest cavities resonated at between 75 and 150 Hz. (cycles per second) depending on the size of the subject, and that was a very uncomfortable feeling. Most coeds did not like their chests 'resonated'. I'm not making this up. We also checked the wear on our phono stylus using an electron microscope.
Loud bass tones under 75 Hz. would not resonate the chest cavity in our test, but would cause some stomach discomfort. What we would could not experiment with at the time, with no subwoofers, was frequencies under about 30 Hz. Much later, two subwoofers I built in the 1990s, six cubic foot monsters in my living room, can play clean test signal tones in the 15 to 25 Hz. range, where bass frequencies are felt, more than heard. Fortunately, there's not much music on CDs below 30 Hz., because loud test tones at those frequencies create discomfort in just 10 to 20 seconds.
Noise is a big problem with wind turbines.
More than just the audible sound -- also the infrasound -- which travels a long way. Wind projects in rural areas may be near homes. So there's no escape from discomfort, and annoyance, beyond moving. Typical symptoms are Insomnia, dizziness, heart problems, and perception disorders.
Regulations of audible noise will use sound pressure meters operating on the sound pressure A-Weighting scale. That scale assumes hearing damage is mainly from frequencies above 500 Hz., so it rolls off the measurements by 12 dB per octave (a lot) below 500 Hz. When I am setting my parametric equalizer for my subwoofers, I use the "flat" C-weighted scale on my sound pressure meter. The C-Weighting (dBC) captures all the bass, while the A-Weighting (dBA) deliberately does not. There is some scientific disagreement over whether hearing loud bass frequencies, at a concert, make the ears even more susceptible to hearing loss at high frequencies.
So a 40 dBA (averaged) daytime sound pressure limit (aka "volume"), as a local regulation, or a nighttime limit of 35dBA, means very little for bass frequencies, especially infrasound frequencies, when using the A-Weighting on the sound pressure meter.
The description of the sound impacts of wind mills as “torture,” by people living nearby, has been repeated across the world. The industry covers it's back with a $2.1 million dollar study from Canada ( the Health Canada Wind Turbine Study ), and the Massachusetts Impact Study.
But a more recent Finnish study found that infrasound (IS) showed no significant reduction in damage until over 15 kilometers from wind farms ! That's surprising -- I would have guessed 1.5 kilometers, not 15. The study was carried out by the Finnish Association for Environmental Health (SYTe), in spring 2016.
" ... after the construction of wind power plants, usually within a few months,
people in the surrounding area have begun to get a wide range of symptoms." says Markku Mehtätalo, Chairman of the Finnish Association for Environmental Health.
Low-frequency sounds (including sounds in the infrasound (IS) frequency spectrum) can cause high levels of annoyance and distress. IS promotes more severe medical symptoms, ranging from sleep disturbances, headache and dizziness, to panic attacks and depression.
THE SAD STORY
OF INSA BLOCK:
Infrasound victim Insa Block, said: "After five or 10 minutes, I feel kind of dizzy. My heart starts to race and I get this massive ringing in my ears. To some extent, I also feel claustrophobic and stressed. When I was lying in bed, I actually noticed the vibrations on the mattress. I had this strange feeling that something was wrong. Then in the half-light, I clearly saw the mattress move several centimeters. When the buzzing starts, it’s like you are in a beehive. You just need to put your hand on the wall of the house, and feel the vibrations ... "
Insa Bock lives in East Frisia, near the town of Esens, located about 700 meters from her home is a wind farm with a few dozen wind turbines. Since they function even at low wind speeds, the wind park can be in operation virtually 24-7.
Professor Alec Salt from the Washington School of Medicine, in St Louis, is an internationally recognized expert on the physiology of the inner ear. "We discovered that if you went down to very, very low frequencies ... we discovered even 5 hertz was getting lovely results. When a human is exposed to infrasound, that sound is going to go into their ear. ... They don’t hear the sound at all, but there’s still electrical responses in the ear, to the sound."
Professor Simone Kühn and her colleagues had exposed test persons to brief infrasound signals below the auditory threshold. "What was interesting to note was that conditions with infrasound exposure, close to the auditory threshold are somehow special. Intense activity took place in the anterior cingulum, a region of the brain which deals primarily with conflict situations, and also in the right amygdala, the region which is linked to stress management ... "
Professor Christian-Freidrich Vahl is Director of Cardiac, Thoracic and Vascular Surgery at Mainz University Medical Centre. Over the last two years, he and his team have devoted their research to the subject of infrasound.
The researchers are studying human heart muscle fibers. Two fibers from the same patient are isolated -- the specimens are still alive. One will serve as a control, the other will be exposed to infrasound in the form of a 16 Hz. frequency for one hour. Christian-Friedrich Vahl: "We can definitely say that under these acute conditions, infrasound really does have a distinct effect on heart muscle tissue. Both series of tests have revealed a clear reduction in heart muscle strength. Whether we hear it or not, every form of energy has physical effects, and infrasound is particularly dangerous, because we don’t hear it."
The global wind industry has systematically sought to silence wind turbine hosts and neighbors with property buy-outs and non-disclosure agreements. Something is wrong here, not getting proper attention, beyond the intermittent, expensive energy from wind turbines.
From the second article:
Infrasound occurs where large masses are in motion, such as avalanches and earthquakes. Infrasound in industrycan come from very large machines, such as automotive sheet metal presses, and from dynamite blasting. Unfortunately, wind turbines also generate infrasound when their blades rotate.
Turbines also make other annoying noises, kill lots of birds and bats, provide expensive electricity, and intermittent electricity. They are "total losers", as President Trump might have said, compared with nuclear power.
MY PERSONAL
EXPERIENCES
WITH INFRASOUND
INSIDE HOMES
Infrasound is defined as frequencies below 20 cycles per second,or 20 Hz. My extensive experience designing, building, testing and equalizing subwoofers, since the early 1980s,results in a different definition: Below 30 Hz. As frequencies decline below 40 Hz., you will increasingly FEEL the sound with your body, more than you HEAR it with your ears. At 30 Hz. what you actually "hear" will mainly be the harmonic distortion at 60 Hz. and 90 Hz., not the 30 Hz. test tone.
Rooms inside a home also have bass resonances at frequencies related to
the room's dimensions. The bass resonances,inside rooms are usually
called standing waves -- they are actually positive feedbacks that amplify certain low frequencies. The lowest bass resonance in a room will be from reflections between walls of the room's largest dimension. The walls do not have to be parallel.
In a larger room, one room resonance is likely to be below 30Hz. For homes
with a relatively large interior open space, perhaps a kitchen, dining room,
and living room, the three room area can resonate at a specific frequency --
likely to be in the infrasonic range. As a result, of room bass frequency resonances, listening and measuring outdoors, where the measurements almost always take place, can be very deceptive. The noise inside a home can be far MORE annoying than outside the home.
Low frequencies from OUTSIDE the home can excite a standing wave inside a room, which amplifies the noise problem. This could be even more annoying if the outdoors infrasound is a pulsing sound like the sound from a wind turbine.
I've had a ridiculous amount of experience with infrasound frequencies inside a home, from the mid-1980s to the mid-1990s, as part of a southeastern Michigan audio club, where building self-designed subwoofers was encouraged. With these monster subwoofers, club members soon found out very few compact discs had very deep bass, much less having the infrasound they wanted to show off their great designs.
So audio consultant Dave Clark's company measured and found the few CDs that had the ultra low bass club members wanted to show off their do it yourself subwoofers. During one audio club meeting, I was driven out of audio consultant Tom Nousaine's home by infrasound from the best subwoofer designed by any Michigan audio club member, described in an audio magazine article as: "The Subwoofer That Shook The World".
I don't think Tom would have appreciated me throwing up inside his large listening room, in response to his incredible subwoofer. I rushed outside, feeling weak and nauseous, from my internal organs getting "all shook up". A few other audiophiles moved outside too, and we were surprised the loud bass / infrasound did not seem to affect all the other club members. While outside on the back deck, a few of us wondered if infrasound could ever be developed into a weapon. We all knew deep bass, especially infrasound,
is omnidirectional -- so we had no idea how you could aim it at the enemy, without harming your own troops.
And it seemed that most people were able to tolerate infrasound energy, at least as part of "music", which added up to a not very effective military weapon.
U.S. MILITARY INFRASOUND
WEAPONS EXPERIMENTS
Colonel John B. Alexander,headed a department that developed unorthodox weapons, including an infrasound weapon. Alexander said: "There were some people who were physiologically affected. They were nauseous. They would get dizzy. There were some who had psychological issues, fear factors, inability to think, kinds of things. We found that some people are affected dramatically. Some people are affected a little bit, and others not at all. From a weapons perspective ... ( we need to ) know exactly what the effects are going to be."
The US military gave up on an infrasound weaponafter 2000, because ts effects on people were too random: Some targets were seriously debilitated; others not much. Just like my own experience during that audio club meeting !
WIND TURBINE
NOISE PROBLEMS
IN GERMANY
"Wind farms" have existed for more than two decades. Germans know a lot about wind turbine noise problems, because they have 30,000+ industrial wind turbines ! Some of their wind farms border on residential areas, and some people there are having trouble sleeping. It took a long time for people to realize their health problems were being caused by wind turbine noise.
Doctors believe between 10% and 30% of people react negatively to infrasound. Problems include Insomnia, heart problems, perception disorders, and dizziness. Germany’s Max Planck Institute identified sub-audible infrasound as the cause of stress, sleep disruption and more.
A Swedish group showed the pulsing nature of the low-frequency wind turbine noise ( ‘amplitude modulation’ ) was responsible for sleep problems.
In Germany, health problems ramped up a lot aftersmall, old turbines were replaced with bigger, more efficient models, a change promoted by the German Environment Agency. But German officials were not concerned about infrasound coming from wind farms -- they claimed that beyond 700 meters, the wind turbine infrasound noise was drowned out by other outside sources ofinfrasound noise. I'm confident that conclusion was caused by two errors:
(1)
The great difficulty of measuring outdoor infrasound with conventional sound measurement equipment, and
(2)
What matters much more is what people hear inside their homes, where they spend most of their time, and where they try to sleep eight hours a day.
FINALLY, WE HAVE
THE FIRST ACCURATE
INFRASOUND OUTDOORS
MEASUREMENTS
The Federal Institute for Geosciences and Natural Resources ( the BGR ), operates a measuring station, called the I26DE, for the German government. I26DE is part of an international monitoring network designed to ensure that terms of the nuclear test ban treaty are observed.
They measure infrasound very close to the ground, because wind noise can trick any measurement device. Their measurement system is a few meters underground, using garden hoses to conduct the infrasound signals from the various inlets, to a very sensitive micro-barometer.
A problem developed: Infrasound from wind farms could affect measurements taken by the I26DE Station, so in 2004 the BGR decided to measure the infrasound emissions from a single wind turbine. Every time the wind turbine blade passed the tower, large air volumes were compressed and sheared. This signal produced an infrasound signature called: "blade pass harmonics".
The blade pass harmonics clearly emerge from outdoor background noise, with a higher acoustic pressure level. The wind turbine studied in 2004 was very small unit, barely 0.2 megawatts. For bigger wind farms, the scientists developed a model for calculations. Their model says that a five megawatt wind turbine, could generate a detectable infrasound signal from a distance of 20 kilometers !
20 kilometers is MUCH longer than the German Environment Agency claimed -- they said the infrasound emissions from wind energy plants, were lost in the background noise, at a distance beyond 700 meters !
The huge difference is from incorrectly measuring broad bands of frequencies, rather than individual frequencies that would clearly capture the specific blade pass harmonic frequencies. The broad frequency bands measured obscured the power of the specific narrow frequency blade pass harmonics.
THE SAD STORY OF
HERMANN OLDEWURTEL
Mr. Oldewurtel lives about 700 meters from a Finnish wind farm, with a few dozen wind turbines that function even at low wind speeds. Oldewurtel said: "If you sleep here for four or five days, you feel like you’ve been out drinking for a whole week. It’s that bad. You get those total mental blank outs. It’s even happened to me on the phone. I couldn’t believe it, but if I’m out and about, or if I go away for a few days, I’m as right as rain again."
Oldewurtel commissioned measurements by expert Sven Johannsen, after the government refused to do measurements. Johannsen used microphones and vibration sensors to measure the home's interior and exterior. And a micro-barometer to record minute air pressure fluctuations. His measurements showed powerful home vibrations, and extremely high infrasound levels inside the home -- even higher acoustic pressure levels
than measured outside the home !
A noise survey done by the government perhaps using something like the DIN 45680 ( the German Standard ), would have ignored the infrasound frequencies.
INFRASOUND TRAVELS
FOR MANY MILES
I was stunned by the studies showing how many miles wind turbine infrasound can travel. I had expected no more than one mile / 1.5 kilometers. Infrasound should travel in all directions ( omnidirectional ) from a wind turbine, not just down wind. The Finns have found the safe setback distance from wind farms to homes is 15,000 meters, not the 1,000 meters planning rules typically permit. A team of German researchers tried to find out what their fellow countrymen are being exposed toat distances of over 20 kilometers !
Government rules to use a lot more "renewable" energy in the future, are overwhelming the "little people" suffering negative side effects from the noise, especially from infrasound noise.
But then ... Why should governments care about infrasound, that no one can actually
hear with their ears, when they also don't care about the high cost of wind generated electricity, or its intermittent electricity output !
2016 FINLAND STUDY DETAILS:
From a translation of the Finnish Association for Environmental Health (SYTe) study in spring 2016: The damage caused by infrasound from wind power plants will only decrease significantly more than 15 kilometers away from the wind turbines !
The data were collected from Satakunta and Northern Ostrobothnia, mainly from areas where wind turbines were built 0.5 to 1.5 years before the interview.
Fifty families, with about 200 people,were studied. The basic research question was whether the family had noticed changes in health status in the last six months to a year. Interviewees were NOT told in advance about the possible connection with wind turbines.
There were many mentions of sleep disturbance, changes in the need for more sleep, fatigue and various pains. Few respondents had ever considered the wind turbines as a possible cause. Harmful or severe health symptoms were three times more common near wind turbines. Symptoms decreased significantly only over 15 to 20 kilometers from the wind power plants ! After the construction of wind power plants, the majority of people in the nearby vicinity are having symptoms, mainly related to stress.
In 2017, additional infrasound measurements, made in different parts of Finland, found out that 15 to 20 kilometers is a typical maximum distance where the infrasound pulses of wind turbines could be measured.