By: Rosemary Stephen PMed, (cert) EOH, IPM, Elements: Environmental Health Intelligence
There is a segment of the general population who cannot live close to wind turbines; if such turbines are installed, they complain that their quality of life is greatly affected. Are these people really experiencing symptoms or are they just expressing a “not in my backyard” attitude? While preparing this blog, I found strong disagreement among the wind farm industry, researchers and environmentalists as to the validity of these claims.
In general, humans can perceive audio frequency ranges between 16 to 20 Hz (cycles per second) at the lower limit of hearing and 16 to 20 kHz (20,000 Hz) at the upper limit. Infrasounds are in the lower range, at or below, the 20Hz frequency range [1,2]. Having, however, conducted hearing tests in the past, I know that a small percentage of the population have a very acute sense of hearing; one person I tested, a jet pilot in the military, could pick-up sounds at -30 dB. A 1998 study done in the Netherlands “indicated that 15% of the population is possibly involved (affected), 3% definitely” experiencing “sensations that may be attributed to low frequency or even infrasound” [3,4]. For the segment of the population who can perceive infrasound, the frequency resembles a loud, continuous, highly irritating noise [5,6].
Infrasound also induces vibrotactile sensations [1F] in sensitive people. Infrasound, unlike other sounds, has no pitch [2F], but instead has a “discontinuous sound in character with a sensation of pressure at the eardrum from around 10 Hz and lower. It is even possible to count the cycles of the tone” [7]. Humans can experience a feeling of pressure in the lumbar area, the buttock, the calf and thighs. These sensations also may be experienced in the upper chest and throat area [8].
The are many symptoms recorded in medical and folkloric literature associated with exposure to infrasounds. A five minute exposure to 10 Hz can cause dizziness while exposure to 12 Hz may cause long lasting nausea. Surf produces an audible boom that emits at 16 Hz; some people, if exposed for hours to this boom, may require hospitalization [9]. Exposure to waterfalls and the lapping of waves can induce nausea in sensitive people [10]. The Aurora Borealis with their swish, crackle, sizzle, and thunderous sounds have been known to induce irritability and nausea in some members of the Inuit population [11]. Infrasounds from winds can cause anxiety and fear [12]; the Mistral, a fierce cold winter wind in France and Sardinia is responsible for seasonal nervous exhaustion, emotional tension, irritability and depression [13, 14] while the Santa Ana winds in southern California are believed to create tensions that can easily erupt into violence [15]. Jet pilots may experience very damaging effects when exposed to infrasound. Effects include decreased equilibrium, disorientation as well as vision and speech impediments, causing the military to limit flight times. Infrasound is also used commercially. It can instill feelings of awe or fear; movie sound tracks and special effects have taken advantage of this to heighten these sensations for the movie goer [16].
But what about wind turbines ?
Although the above symptoms have been documented, almost all research done on infrasound does not regard wind turbines as having adverse health effects on humans. In “The Health Impact of Wind Turbines: A Review of the Current White, Grey, and Published Literature” [17] the author states that “The health impact of the noise created by wind turbines has been studied and debated for decades with no definitive evidence supporting harm to the human ear” and “Although noise tolerance is very subjective, care should be taken to ensure a reasonable noise level exists in relation to normally occurring sounds within the environment” [18] . Even Greenpeace in its 2006 report entitled “Global Wind Energy Outlook” concluded that “wind turbine noise is comparatively lower than road traffic, trains, construction activities, and industrial noise”. Howe Gastmeier Chapnik Engineering also completed a study in 2006 on infrasound emitted by Canadian wind farms. Their results indicated that “wind farms do generate infrasound however, it is not at a level perceptible to the human ear”. This is in agreement with research done by the Danish Wind Industry Association and the Danish Environmental Agency, The German Wind Energy Association and the UK [19] who state that “if proper setbacks are established, there should be no adverse health effects” [20].
Neil Kelly of the U.S. National Renewable Energy Laboratory and other U.S researchers, however, have noted, there is a difference between wind turbines installed downwind and those installed upwind; more low frequency noise is emitted by the downwind turbine configuration, likely “due to wakes arising from tower structural elements” [21, 22]
The issues surrounding wind turbines are complex. Wind energy is seen as a ‘green energy solution’ that is renewable and generally good for the environment. These turbines, however, also emit infrasounds. It is clear that some people can hear and physically perceive infrasound, resulting in a reduction in the quality of life and even health problems. The question then, is how can these issues be resolved ? In Part III of this series, we will look at what protection standards industries and governments are proposing to reduce wind turbine noise and to solve potential health effects.
Rosemary Stephen PMed, (cert) EOH, IPM (2010). Wind Turbine Syndrome, Part II Elements: Environmental Health Intelligence
End Notes:
[1F] Vibrotactile sensations: detecting and interpreting sounds via the sense of touch.
Vibrotactile aid (2004) MedicineNet.com (on-line) Available: http://www.medterms.com/script/main/art.asp?articlekey=13307. Cited 2010 Apr 16.
[2F] Pitch: an element of a tone or sound determined by the frequency of vibration of the sound waves reaching the ear; the greater the frequency, the higher the pitch
Pitch Definition, Music, Acoustics (2010) Your Dictionary.com. (On-line) Available: http://www.yourdictionary.com/pitch. Cited 2010 Apr 16.
[3F] Hearing threshold: the sound level below which a person’s ear is unable to detect any sound. OdB is the reference level for adults.
Hearing threshold (2009) GreenFacts. (On-line) Available: http://www.greenfacts.org/glossary/ghi/hearing-threshold.htm. Cited 2010 Apr 16.
References:
[1] Moller, H. and Pedersen, C.S. Hearing at low and infrasonic frequencies. (2004) Department of Acoustics, Aalborg University, Denmark, Noise and Health. (On-line) Available: http://www.noiseandhealth.org/article.asp?issn=1463-1741;year=2004;volume=6;issue=23;spage=37;epage=57;aulast=Moller. Cited 2009 Jul 30.
[2] Infrasound (2009) The free encyclopedia, Wikipedia. (On-line) Available: http://en.wikipedia.org/wiki/Infrasound. Cited 2009 Jul 31.
[3] Vaisman, D. The Acoustics of War (2002) Cabinet. (On-line) Available: http://www.cabinetmagazine.org/issues/5/acousticsofwar.php. Cited 2010 Apr 22.
[4] van den Berg, M. Influence of Low Frequency Noise on Health and Well-being (2005) Informal document No. GRB-41-8. (On-line) Available: http://www.unece.org/trans/doc/2005/wp29grb/TRANS-WP29-GRB-41-inf08e.pdf. Cited 2010 Apr 22.
[5] Moller, H. and Pedersen, C.S. Hearing at low and infrasonic frequencies. (2004) Department of Acoustics, Aalborg University, Denmark, Noise and Health. (On-line) Available: http://www.noiseandhealth.org/article.asp?issn=1463-1741;year=2004;volume=6;issue=23;spage=37;epage=57;aulast=Moller. Cited 2009 Jul 30.
[6] Infrasound (2009) The free encyclopedia, Wikipedia. (On-line) Available: http://en.wikipedia.org/wiki/Infrasound. Cited 2009 Jul 31.
[7] Moller, H. and Pedersen, C.S. Hearing at low and infrasonic frequencies. (2004) Department of Acoustics, Aalborg University, Denmark, Noise and Health. (On-line) Available: http://www.noiseandhealth.org/article.asp?issn=1463-1741;year=2004;volume=6;issue=23;spage=37;epage=57;aulast=Moller. Cited 2009 Jul 30.
[8] Ibid. Cited 2009 Jul 30.
[9] Gavreau, V. Dr. Chapter 8, Deadly Sounds (1999) Lost science. (On-line) Available: http://www.hbci.com/~wenonah/history/gavreau.htm. Cited 2009 Jul 31.
[10] Ibid. Cited 2009 Jul 31.
[11] Ibid. Cited 2009 Jul 31.
[12] Ibid. Cited 2009 Jul 31.
[13] Ibid. Cited 2009 Jul 31.
[14] The Infamous Mistral Wind in Provence (2010) FrenchEntrée.com. (On-line) Available: http://www.frenchentree.com/france-provence-living/displayarticle.asp?id=17217. Cited 2010 Apr 09.
[15] Chandler, Raymond, “Red Wind”, Dime Detective, January 1938. Quotation from: Santa Ana Winds, Santa Ana Winds in Popular Culture, Wikipedia, the free encyclopedia. Available at: http://en.wikipedia.org/wiki/Santa_Ana_winds. Cited May 19, 2010.
“It was one of those hot dry Santa Anas that come down through the mountain passes and curl your hair and make your nerves jump and your skin itch. On nights like that every booze party ends in a fight. Meek little wives feel the edge of the carving knife and study their husbands’ necks. Anything can happen.”
[16] Infrasound (2009) The free encyclopedia, Wikipedia. (On-line) Available: http://en.wikipedia.org/wiki/Infrasound. Cited 2009 Jul 31.
[17] The Health Impact of Wind Turbines: A Review of the Current White, Grey, and Published Literature (2008) Chatham-Kent Public Health Unit . (On-line) Available: http://www.wind-works.org/LargeTurbines/Health%20and%20Wind%20by%20C-K%20Health%20Unit.pdf . Cited 2010 May 12.
[18] Ibid. Cited 2010 May 12.
[19] Low Frequency Noise and Wind Turbines (2005) British Wind Energy Association. (On-line) Available: http://www.bwea.com/pdf/lfn-annex.pdf. Cited 2010 May 12.
[20] The Health Impact of Wind Turbines: A Review of the Current White, Grey, and Published Literature (2008) Chatham-Kent Public Health Unit . (On-line) Available: http://www.wind-works.org/LargeTurbines/Health%20and%20Wind%20by%20C-K%20Health%20Unit.pdf . Cited 2010 May 12.
[21] Kelley, N. Wind turbine noise (2010) The Encyclopedia of Alternative Energy and Sustainable Living. (On-line) Available: http://www.daviddarling.info/encyclopedia/W/AE_wind_turbine_noise.html. Cited 2010 May 12.
[22] Low Frequency Noise and Wind Turbines (2005) British Wind Energy Association. (On-line) Available: http://www.bwea.com/pdf/lfn-annex.pdf. Cited 2010 May 12.
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Does infrasound affect you in any way if you are not from the sensitive segment of the population and cannot generally hear or feel it ?
Wait a minute.. so are you saying that someone has managed to prove that auroras actually make sounds perceivable from the ground? The last I’d heard on that was that some people claimed to hear sounds but that no one had managed to demonstrate that such sounds even existed.
Why are your links hidden at the bottom of the page? Why not place them conveniently in context? Then they can be used at the time they are needed. It makes your article unfriendly and hard to read.
Hello Bob,
Thanks for the critique ! We will add links within our posts to make it easier to follow up with the references.
R.
Hello,
Yes it does. Even if most of us do not hear them, the body does react to them. People feel as if they sense a ghost and it can cause nausea, headaches and anxiety.
This reference below shows elephants reacting to infrasounds. Here is the link. Check the YouTube video.:
Infrasound: The sound too awesome for us to hear
http://io9.com/5534859/infrasound–the-sound-too-awesome-for-us-to-hear
R.
Hello,
Yes it does. Even if most of us do not hear them, the body does react to them. People feel as if they sense a ghost and it can cause nausea, headaches and anxiety.
This reference below shows elephants reacting to infrasounds. Here is the link. Check the YouTube video.:
Infrasound: The sound too awesome for us to hear
http://io9.com/5534859/infrasound–the-sound-too-awesome-for-us-to-hear
R.
Hello Nomad,
You are correct, there is still controversy over sounds emitted from aurora borealis. Since there is controversy, we want to present the wide range of information available and allow you to draw your own conclusions. To that end, here are some articles to consider — the first article entitled “Straining to Hear the Voice of the Aurora” presents anthropological and personal accounts of the “whistling, rustling, crackling sounds” emitted during a light display. This article also suggests what may produce these sounds.
The second article, “Case study: Sound Art Jacob Kirkegaard” talks about Jacob Kirkegaard, a young musician who is integrating nature sounds into his music. Although this article is sponsored by a company which specialized in sound measuring instruments, it will answer part of your question about the ability of measure sounds we do not hear. The article does not mention infrasounds, but it gives you an idea of how to measure sounds below the hearing threshold.
The third article “Damn interesting: The Sound of the Aurora” explains, in more scientific terms, the different theories on how Aurora borealis sounds are produced. The fourth article, “Auroral Sounds”, basically explains in greater details the most popular theories on Aurora borealis.
Last but not least, is the actual taping of an Aurora borealis display. We selected the first video just to see if we could actually hear sounds emitted by the light. It appears that on a machine with a good speaker system you can hear sizzing and popping noises as described in the first article. The question is, of course, are we hearing the aurora or interference….
We hope that you will enjoy reading about Aurora borealis and maybe even hearing their peculiar music.
Straining to Hear the Voice of the Aurora Article #1257
by Ned Rozell
http://www.gi.alaska.edu/ScienceForum/ASF12/1257.html
Case study, , Sound Art Jacob Kirkegaard (2005) DEnmark Media Art. (On-line) Available:
http://www.bksv.com/doc/ba0764.pdf
Damn interesting The Sound of the Aurora
Richard Solensky 16 November 2007
http://www.damninteresting.com/the-sound-of-the-aurora
Auroral Sounds
http://auroralsounds.tripod.com/
BNVN , Breaking news Video Network
Aurora Borealis Video
http://www.bnvn.com/?q=content/aurora-borealis-or-northern-lights-video-and-lunar-stock-video-archive-page
http://www.bnvn.com/videoplayer/detail.php?id=478
Amid the traffic and the clicking of the camera, you can hear crackling and popping, perhaps from the lights.