Bruce McPherson Infrasound and Low Frequency Noise Study

Bruce McPherson Infrasound and Low Frequency Noise Study Dec. 14, 2011
Stephen E. Ambrose, INCE (Brd. Cert.) and Robert W. Rand, INCE Member

The study confirms that large industrial wind turbines can produce real and adverse health impacts and suggests that this is due to acoustic pressure pulsations, not related to the audible frequency spectrum, by affecting the vestibular system especially at low ambient sound levels. The study results emphasize the need for epidemiological and laboratory research by medical health professionals and acousticians concerned with public health and well-being. This study underscores the need for more effective and precautionary setback distances for industrial wind
turbines. It is especially important to include a margin of safety sufficient to prevent inaudible low-frequency wind turbine noise from being detected by the human vestibular system. Read study

24 thoughts on “Bruce McPherson Infrasound and Low Frequency Noise Study

  1. It is not a company, it is a professional designation. These people are certified under the International Institute of Noise Control Engineering.

  2. Again, Wind Works Power Corp-Form 8-K-Februrary 2,2010
    Bottom of page 3:
    “Also turbines create a noise parameter which circles out a portion of the land and which parameter has to be fitted in with the setback towards any structure” and use search for Wind Works Power Corp-Form 8-K-February 2,2010. WWPC acknowledged noise parameter to USSEC on Feb.2,2010.
    Also mentions 550 meter setbacks but when was 550 meters first mentioned? And by whom?
    Forms 8 & 10-K and other SEC forms are legal documents.

    • Hey Barbara,
      I’ve been watching Wind Works (Golden Goose) for months.
      There SEC filing dated Feb. 2 – 2010 – was a joke!
      No financials to speak of – although, they proved they had no money.

      They filed another 8-K @ 4:57pm on Aug. 9, 2011
      – but, then it was removed or withdrawn. Well – I can’t find it.
      Very strange. or, maybe not.

      Barb – from the info you posted:
      They had one sale fall apart, but –
      their other sale to REpower – I believe is still on – closed, or is conditional – and will close etc…….not sure.

      All eyes should be on this company – for educational purposes – of course!

      • Lots of BS about why IWTs are necessary but this is a small company so you can’t expect much in the way of financial information. Appear to have plenty of debt due to financing IWTs. But they did admit to a noise parameter and saftey issues. Don’t recall any noise admissions by any wind company. What is this company telling Ontarians about noise & safety issues at their information meetings? At least “noise parameter” is in a written legal document.

      • Form 8-K Feb.2,2010, p.3, “create a noise paramater” is included in information as to why a turbine/turbines mught have to be shut down thus reducing investor income.
        Form 10-K Oct.28,2011,p.13, “icing” & “damage” due to extreme weather which could also reduce investor income. Reducing investor income will cause a stock to lose price value. Potential for falling stock price must be disclosed.
        Parameters could involve distances but how much distance is not revealed. Parameter also means a determining factor or characteristic.
        IWTs do create a characteristic “noise'” which circles out a portion of the land.

  3. I still believe that ‘Annoyance’ from Infrasound and low frequency sound is a response to the impacting Intensity (not the Sound Pressure Level) of the wind tower emissions.
    The Amplitude modulation has the same frequency as the blade passes and the peak intensity occurs when the rate of change of sound pressure is at a maximum :- that is when the blades are passimg behind the support column.

    That is why the annoyance sensation peaks at every blade pass.

    The detection mechanism is much more likely to be by cutaneous perception than to be the detection of inaudible frequencies by the auditory system.

    Intensity correlates with the magnitude of the ‘Annoyance’. That is not to say that the audible emissions from towers are no nuisance. The problem is that the carry distance of the inaudible infrasound affects a far greater area.


  4. On reflection I should expand my earlier comment: Please pass it on to Stephen Ambrose.

    The conclusion that the emissions had tonal content at 22.9 and 129 Hertz is interesting. That fits with what I call the Loewenstein/Nangini effect of ” vibrotactile evoked …steady state responses in the human somatosensory cortex”.

    This supports the probability that annoyance is due to cutaneous detection of the impacting sound energy and that early detection by the vestibular system is not involved. At 129 hertz the peaks are spaced some 8 ms apart . This is firmly inside the 7 to 10 millisecond range for peak spacings to cause repetitive ‘firing’ of pacinian corpuscles.(Werner R Loewenstein, Journal of General Physiology, September 9 1957).
    That intermittent bands of this repetitive firing can cause a detectable steady state response in the cortex was published by in Neuroimage 2006 October 15 by Nangini C, Ross B, Tam F, and Graham SJ.
    My amateur researches suggest quite strongly that it is this pattern of well spaced high intensity pulses (most wind turbines have a column pass frequency of 1.25 Hertz not 23 Hertz) with the supporting low frequency emissions in the range of 100-200 Hertz. cause the Annoyance.


  5. Henry’s Postscript 2.

    The same Annoyance can be induced by a combination of a puimped water supply (causing building vibrations at infasound frequencies) and the emissions from three phase electrical sub-stations. Annoyance seems to occur when these coincide.
    A very common energy source for low frequency sound seems to be building vibrations induced by fluctuations in mains water pressure. Hence the ‘Hum’ found in hilly urban situations.

    The source of my, very painful, sensitisation is building collisions varying between 0.5 and 8 Hetrtz accompanied by airborne sound at 185 Hertz. The immediate cause was resonance within a substantial unvented hot water system with fluctuations in the pumped water main flows.
    The energy consumed in pumping has to be emitted somewhere.

  6. Excellent open-minded work on the Bruce McPherson ILFN Study.

    1) I think one of the main conclusions that need to be emphasized to refute studies claimed to discount Bruce McPherson ILFN Study (such as is that a main concern is not sound, but infrasound — or simply pressure waves.

    And that there is therefore no justification for any weighting (A or even G), since these are based on favouring specific frequencies, such as those based on sound perception.

    Until there is an equivalent “equal-loudness Fletcher-Munson” curve for the feeling of nausea and dizziness, all work should therefore be done on unweighted linear measurements.

    2) It also appears that there needs to be an accepted way to quantify the peak to average pressure differences at the blade passing rate (for example, at about 1.4 Hz), as most measurements ignore this by taking a longer-term average of the pressure levels without noting that the crest factor or repetition of this peak noise may be important.

    I note that studies such as are done by very qualified and competent people, but they make assumptions that cause them to reach unjustified conclusions (for example, just because G-weighting may match some definition of infrasound, this doesn’t justify using G-weighting when measuring wind turbine noise as G-weighting has not been shown to correspond to any human sensation).

    3) Perhaps what is needed is a new weighting based on the blade passing frequency, to help ignore other constant background noise and to ensure that longer-term averaging doesn’t result in the frequencies in the swoosh being ignored in reports. The recorded data would be post-processed to identify the very slowly changing blade passing frequency. Then only pressure waves that have that blade passing frequency component would be included in the new weighting.

    4) It would be helpful to have “double blind” testing on volunteers in a controlled environment, done with aritificially-generated infrasonic pressure waves to determine if there is a correlation between these low frequencies and the nausea, dizziness, and other negative effects reported. This would be more useful than trying to use the thresholds determined by Dr. Alec Salt.

  7. The report actually doesn’t, as the subtitle states, actually confirm adverse health effects by large industrial wind turbines. While I accept the detailed acoustic measurements as presented, most of the health effects reported were based on the personal experiences of the two investigators. Even a naive member of the public knows that a health study would require a much larger sample size and would not include the investigators. Surely there are known objective methods of measuring the stated physiological effects observed by the researchers (nausea, anxiety, inability to perform mechanical tasks). If the cause of the physiological resposes observed are from the wind turbine sound, there also must be ways to simulate this in some more controlled experimental environment to confirm its effect on study subjects. I can’t believe this has not already been studied (in a military contect, for example). This can’t be very hard since the report’s authors experienced effects within 20 minutes (which in itselft is both alarming and suspicious).

    • Even a naive member of the public knows that a health study would require a much larger sample size and would not include the investigators.

      And if that is not possible? Then what? Of course if we install 9000 turbines would that be more objective? Would it be a good idea?

      Any chance you could volunteer to live in one of the affected houses? Would that be objective enough?

      If “it is not very hard” then perhaps you could suggest a mechanism. But I do note that was not the objective of their particular study…. in any case, it should be easy to get a grant to study this if you are correct. Why not apply? Why has CANWEA not performed this “conclusive experiment” (whatever it may be) to demonstrate the absence of problems (whatever they may be). It seems easy — does it not?

  8. Even if the two investigators are part of the small group of persons who are pre-sensitised to react to the infrasound emitted by wind turbines, there is a potential concern. As far as I am aware there have been no published studies of the proportion of the population affected.
    Nor is it known if the combination of infrasound and ground vibrations from these towers are ever in a suitable form and/or intensity to cause further sensitisation. Clearly the authorities believe that these towers will not cause sensitisation but until the background research is published we just don’t know.


    • However, the report overreaches in its claim that it provides conclusive proof that IWTs cause health problems. The problem with this type of flawed report is that it provides fodder to those who seek to dismiss those who oppose IWTs on health grounds as wiling to grasp at any straw to prove their case. This does considerable damage to your goal of influencing public policy. It doesn’t matter that the report affirms your existing beliefs. The objective has to be to provide the same standard of proof as required by other areas of medicine: a double blind study. The report falls far short of this standard. You damage your case by promoting its findings as proof.

      • I did not see that they claimed conclusive proof. Could you out out the statement please? I really feel I should take them to task if that is true.

        What were the flaws btw. They were not obvious to me.

        I am curious about how you would organized a double blind study on this one –give the context and operating parameters. I look forward to your suggestions…


      • The report’s subtitle appears to claim definitive proof: “Adverse Health Effects Produced By Large Industrial Wind Turbines Confirmed”.

        The flaws in the report are that it makes its claim on a sample of two people which is way too small to be statistically significant. That the two were also the investigators would also never ever be accepted as valid proof.

        To assess the validity of the claims of the authors of this report, a study might involve identifying 100 (say) people who are prone to motion sickness (the authors suggest that this might be the cause of their sensitivity). They would be divided into groups of (say) 5 and brought to the house in question on a windy day when the turbines were operating. They would be told that the turbines would be turned off just after they entered the house. The turbines would be turned off (or not) after they are in the house. . After an hour (the authors claimed health effects after 20 minutes), the responses of the subjects (especially the ability to do tasks requiring manual dexterity) would be measured. No one on the house would know at the time of the test if the turbines were on or off. The differences between the turbine “on”: and turbine “off” groups would be measured. Part of the cost of the survey would be to compensate the turbine owners for lost income. Additionally, testing of subjects in an anechoic chamber using the waveforms measured by the authors could be used to assess whether people are vulnerable to this type of acoustic energy.

        What would it take to convince you that there are no adverse health effects of IWTs.?

        Do not interpret my skepticism on this report as support for IWTs. There is a proposal to build a 40 turbine farm near me. The closest will be 5 km away. I will be able to see all 40 from my house.

      • I suggest you re-read the study. I think you missed some crucial points — as to the number of complaints etc. — i.e. why they were present and performing the study.

        As for correlation and causation according to “The Hockey Team” (TM Climate Science) they are one and the same — kinda like CO2. 😉

        PS: It also matched my results obtained with custom LFN and monitoring equipment. I also happen to be one of the lucky people “upset” and give vertigo by LFN — earthquakes and aftershocks are problematic.

    • IWT “noise” is arelatively new health problem as IWTs have only been used for a limited time near where people live. So not much in the way of health studies has been done around the world as these studies were never needed prior to this time.
      Money for any kind of health study is always in short supply so money was not allocated for a problem that did not exist prior to now.
      It’s easy for all those involved in IWTs to take advantage of this situation where there are very limited health studies. They know they can get all the IWTs installed before enough health information is obtained to stop them form what they are doing.

      • Dave from Ontario:
        I have a degree in statistics so I understand the point you are trying to make. It is admirable that you are concerned about this. But I can tell from your comments that you do not have any direct experience with the wind turbine problem. And most people not familiar would respond the same way. This is likely where a large part of the problem is.

        Have a look at it from a different angle. If someone took a baseball bat up to two people and smacked them in the arm and broke their arms. We do not need to break 100 more arms to decide if hitting people is a problem. I am only talking about the issue of fractured bones here, (in the wind turbine case ears). Not bruising or pain. Out of 100 people some have stronger arms, some don’t get hit as hard so not always fractured bones. The wind turbine problem is very obvious if it happens to someone.

        There is no way to hide wind turbine noise from anyone. Outside of a house the wind turbine noise might be 40 decibel. Other common noises are often much higher, 50 – 70 decibel. Inside of the house the other supposedly louder outside noises can’t be heard. But the wind turbine noise still can be heard. Inaudible low frequency noises are never heard.

        However this does not solve the possible problem of irrefutable prove. So let the human experiments continue?

      • The problem is that IWT “noise” issues are being taken before a tribunal which is in the legal system and being argued by lawyers and “noise” experts before a tribunal of people who do not know about these issues.Laws have been changed so that Galileo type decisions can no longer be made by tribunals and courts.I’m not disagreening that IWTs don’t cause health problems. But these issues are being argued in the wrong venue so I fear the result will be the same as before.

      • If this tribunal is limited to “experts” only testimony on “noise”/sound issues then the victims of IWTs will be excluded because they are not “experts” on noise/sound issues.
        Ian did testify? But Ian was neither a victim nor an “expert” on IWT “noise” so his testimony did not not matter either way as to the “noise” issues.
        The victims of IWT “noise’ should sue one of the IWT developers for health damages and then the victims testimony will be heard.

      • Ian was what is known as a “safe” witness to the opposition in that he is not an “expert” witness and not a victim so no or very little damage could be done to the opposition.

  9. When French scientist Vladimir Gavreau finds his laboratory flooded
    with a mysterious energy that has debilitating effects on the human
    body, his research is taken in a menacing new direction. Did he invent
    a new type of weapon of mass destruction

    show on tv was much more in depth than this Youtube video – shows
    experiments with ultra sound and how debilitating it is

    The Sonic Weapon of Vladimir Gavreau

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