Wind turbines produce major infrasound. Period. No question about it.
Mar 22, 2010
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—Calvin Luther Martin, PhD
For years, Big Wind has denied that turbines produce infrasound & low frequency noise (ILFN). Either denied it exists or dismissed its significance as so trivial, it’s not worth considering. The (convenient) rule of thumb among Big Wind acousticians being, “If you can’t hear it, it can’t hurt you.”
This has been definitively proved wrong. Wrong on two counts.
(1) It turns out the vestibular organs of the inner ear, along with other bodily organs of balance, motion, and position sense, are profoundly affected (“dis-regulated”) by sub-audible ILFN. It turns out that the frequency range of the normal human vestibular system (semi-circular canals, utricle, and saccule) is 0 (DC) to 20 Hz. Yes, this is infrasound, ladies and gentlemen. (Yes, DC means “direct current.”)
“If you can’t hear it, it can’t hurt you” is now “If you can’t hear it, it can’t hurt you.” One of the many “junk science” dogmas consigned to the scrapheap of history.
(2) Secondly, it turns out that industrial wind turbines produce strong infrasound and low frequency noise, precisely in the range (0 to 20 Hz) “listened to” by the vestibular organs—the body’s principal organs of balance, motion, and position sense. There are, now, numerous noise/vibration studies unequivocally demonstrating turbine ILFN. This being one of the finest:
“The Inaudible Noise of Wind Turbines,” by Lars Ceranna, Gernot Hartmann, and Manfred Henger. Presented at the Infrasound Workshop, November 28 – December 02, 2005, Tahiti. Federal Institute for Geosciences and Natural Resources (BGR), Section B3.11. Stilleweg 2, 30655 Hannover, Germany. Click here for the full report (PDF).
This graph demonstrates wind turbine infrasound. Infrasound (which, mind you, is lower than low frequency noise) is defined as noise & vibration less than 20 Hz—except this is “noise” you can’t hear. The point is, your semi-circular canals, utricle, and saccule (vestibular organs) register this—as alarming, confusing signals. These signals disrupt (dis-regulate) these inner ear, vestibular organs. Thus creating the panic (“fight or flight”) response upon awakening in the night, plus the vertigo and nausea, plus the more long-term memory and concentration deficits. Think of it this way: Wind turbines make people seasick, though worse, because it’s long-term. (Graph taken from Ceranna et al., “The Inaudible Noise of Wind Turbines” 2005, p. 14, with overlaid explanatory text by KS.com.)
Internationally acclaimed noise engineer George Kamperman calls it “the best documentation I have seen on wind turbine infrasound. This is a careful study on a single wind turbine utilizing instrumentation appropriate for measuring very low frequency infrasound.”
George Kamperman, P.E., Kamperman Associates
Turn to the final page of the report, p. 23, for the authors’ conclusions: “Wind turbines and wind farms generate strong infrasonic noise which is characterized by their blade passing harmonics (monochromatic signals).”
You can’t get any more explicit than that.
Next time you hear a wind salesman dismiss infrasound and low frequency noise as moonshine, whip out this article and start reading aloud, so the entire roomful of people hears the truth.
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Comment by Ben Hermann on 02/09/2011 at 11:34 am
The original report is available in German. It is the report the above quoted presentation in Tahiti is based on and can be downloaded here.
In its conclusion it does say what is quoted above, but it continues stating that from distances as small as 300m that noise would drown in ambient noise: “Unabhängig von diesen großen erforderlichen Abständen von Mikrobarometern zu Windrädern wird hingegen die menschliche Wahrnehmungsgrenze für Infraschall bereits nach etwa 300 bis 500 m unterschritten.” (Click here.)
Editor’s reply: We used Ceranna et al.’s graph merely because it’s handy. One can find similar graphs produced by Rick James and others—that is, by noise engineers who are honestly studying turbine infrasound as opposed to performing as wind shills.
Be that as it may, it is indisputable that wind turbines produce major infrasound. It would be perverse to argue otherwise.
Let us now reconsider what is effectively your question, “Would not that infrasound be drowned out by ambient noise, from distances as small as 300 m?”
The question, if you understand infrasound, is absurd, for the simple reason that infrasound is not heard—it is felt. By definition, it is below hearing—re-read what I wrote, above—but not below inner ear and brain response. (Bear in mind that Ceranna et al. were noise engineers, not inner ear physiologists or clinicians.)
Neither trees rustling or wind or anything else in the ambient atmosphere is going to “drown out” something that cannot be “drowned out.” This argument is the stock and trade of wind developers, and it’s a cruel hoax. (Hence my obvious annoyance.)
You can read the research of Professor Alec Salt (inner-ear physiologist) and Dr. Nina Pierpont on this site to confirm that infrasound at the levels shown by Ceranna et al.—and since confirmed by many others—can and does produce a vestibular and cochlear response. Click here and here, for instance. Pierpont discusses this at length in her book.
Nice try, Ben, but no cigar.