Vic Health Dept “whitewash” put under the microscope by top Acoustics Professor

A few weeks back, you’ll remember the wind industry, its parasites and apologists crowing long and loud about a piece of tosh dished up by a couple of patsies in the Vic Health Dept – apparently, much to the horror of the Minister – as covered in our post “Red Faces at the Victorian Department of Health“.

rooster-crowing-2

It seems the wind industry and its shrinking caravan of supporters may have cackled just a tad too soon.

Hansen1

Professor Colin Hansen

One of the Top Guns in acoustics, Professor Colin Hansen, from Adelaide Uni, has taken the axe to the Vic Health report.  But unlike its wind industry backed authors (who weren’t game to put their monikers on the Vic Health report), this chap isn’t afraid to get his hands dirty.  With 40 years of field experience, Colin knows a thing or two about getting data before shooting his mouth off.  Currently working with a team of crack independent experts at Waterloo, where his team are actually doing the work to show the causal link between constant low frequency turbine noise, sleep deprivation and other adverse health effects, Colin sent this letter to the Vic Health Dept last week.

LETTER FROM EMERITUS PROF COLIN HANSEN TO VIC HEALTH DEPT
PROF. COLIN HANSEN
SCHOOL
OF MECHANICAL ENGINEERING
FACULTY OF ENGINEERING, COMPUTER & MATHEMATICAL SCIENCES
THE UNIVERSITY OF ADELAIDE SA 5005
AUSTRALIA
TELEPHONE +61 8 8303 5460
FACSIMILE +61 8 8303 4367

colin.hansen@adelaide.edu.au

May 23, 2013

Environmental Health Program
Health Protection Branch
Wellbeing, Integrated Care and Ageing Division
Department of Health
50 Lonsdale Street
Melbourne, Victoria 3000

Dear Sirs,

The reason I felt compelled to write to you is that I have a number of concerns about the accuracy of some of the statements made in your document, “Wind farms, sound and health: Technical information”. By way of introduction, I have been researching, consulting and teaching acoustics and noise control for more than 40 years and have published numerous papers as well as 10 books on the subject.

I find that chapters 1 to 3 contain information that lay people will find very useful. However, later chapters contain statements that conflict with current knowledge in the field and could mislead the public into believing things that are simply not true. I have listed the problem statements below and I sincerely hope that these can be fixed before this document is too widely circulated.

1. The A-weighting network, discussed on page 7 may have been designed to approximate the response of the human ear, but it is a very poor approximation, especially at low frequencies. It is well known that low frequency sound is much more annoying and disturbing to most people than the A-weighted measurement would indicate, especially in the absence of any significant mid- and high-frequency sound. This should be pointed out in the document on page 7.

2. On page 8, the document states that the LA90 or the L90 descriptor is used to measure wind farm noise without any qualification at all. It is well known that sound levels produced by a wind farm can fluctuate significantly and that a descriptor that represents a level exceeded 90% of the time will miss the 90% of the time when the wind farm noise fluctuates above the 90% level, and thus will be a gross underestimate of peak noise levels which define the annoyance value of the sound. The level of fluctuation becomes more noticeable and annoying as the distance from the wind farm increases and energy becomes more low frequency in nature. The best way to distinguish wind farm noise from other environmental noise is to take noise measurements on a number of occasions with the wind farm turned off and then running immediately afterwards.

3. On pages 9 and 10, the document discusses hearing thresholds for low frequency sound and suggests that wind farm infrasound is well below what people could detect. However, it should be pointed out that the hearing thresholds are for steady, single frequency sound in the absence of any other sound. There are two problems with this approach. Hearing thresholds are known to be much lower for fluctuating (or modulating) sound and also when there are many harmonics present at the same time as the fundamental. If we add on to this that wind farm low frequency and infrasound noise measurements that have been taken by a number of people are only Leq or L90 values and do not reflect the peak noise levels which could be 10 to 15 dB higher than the L90 levels, it is possible to get to the point where wind farm low frequency noise and possibly infrasound could be detectable by a significant number of people at distances up to 5 to 10 km from the wind farm, depending on the meteorological conditions.

4. On page 11 the document implies that computer models for predicting wind farm noise can be relied upon to give accurate results. None of the models used for predicting noise take into account the likely increase in turbine noise levels when they are operating in a turbulent atmosphere or in the wake of other turbines. Neither do the models take into account the possible focusing of low frequency sound under stable atmospheric or downwind conditions that can result in much greater noise levels than predicted.

5. The recent study on infrasound mentioned on page 11 had problems with inaccuracies associated with the instrumentation at low frequencies and the use of 1/3 octave filters which completely missed the peak fluctuations in the infrasound. Another problem was the reporting of only dBG results, which not everyone agrees reflects the perception of infrasound. Thus the statement on page 12 that “In conclusion, there is overwhelming evidence that infrasound from wind farms is at levels which are too low to be audible, and no higher than background levels in the environment”, is not true. My research group is currently undertaking noise and vibration measurements at residences affected by the Waterloo wind farm and it can clearly be seen that there exist noise levels at blade passing harmonics that are well in excess of background noise levels. We are also measuring significant levels of impulsive low-frequency sound several kilometres from the wind farm and this can be quite annoying to some people when they are trying to sleep. We intend to publish these results in the not too distant future.

6. The first statement in the conclusions, “the predominant sounds produced by wind farms are in the mid to high frequencies” is misleading. This may be true close to the turbines but at distances that most affected residents live, especially at night during stable weather conditions, it is the low frequency sound that people find disturbing and which is responsible for preventing them from obtaining a good night’s sleep, which in turn can possibly have adverse health effects.

Yours Sincerely

EMERITUS PROFESSOR COLIN H HANSEN
School
of Mechanical Engineering

A pdf version is available by clicking on this link and then on the link that appears in the new window: victorian_health_commentary.

About stopthesethings

We are a group of citizens concerned about the rapid spread of industrial wind power generation installations across Australia.

Comments

  1. Well done Professor. Let the research results speak for themselves with honesty and integrity. Adelaide uni sure could give Sydney uni a few lessons!

  2. Brian & Joanne Kermond says:

    Thank you Professor Colin Hansen for unveiling the true science of the industrial wind turbine factories which our family know only too well as long term wind farm refugees.
    After five years of bewilderment we now have a glimmer of hope that justice and truth will prevail and we can return to our home.

  3. Melissa Ware says:

    Waterloo studies scientifically confirm the wide and detrimental affects of a wind farm. Your letter to the Victorian Department of Health brings further enlightenment to a Government Department in need of a thorough review of their responsibilities of duty of care to overseeing the well being of all the public. There is a ‘pandemic’ of wind farm victims and refugees with genuine, life depleting health complaints due to infrasound and noise disturbance. The Health Department has the authority to respectfully recognise the issues, show responsibility and no longer pass it to other departments or local GP’s, ignorant or dismissive of the health complaints being experienced.
    This Waterloo report is long awaited with much anticipation and I offer a heartfelt and true, simple, thank-you to Professor Hanson.

  4. Thank you Professor COLIN HANSEN for setting the record straight. We hope that you and your team don’t get too ill at Waterloo.

  5. Good on you Professor Colin H Hansen. By writing to the Victorian Health Department, you have helped me to regain some of my faith in our Nation’s science profession.

    All the people that are speaking out about the effects of the noise & infrasound from industrial wind turbines, do know what they are talking about, as the effects are real.

    People like Chapman should have their titles taken away from them as they are putting out information that is untrue (real people call them liars).

    The more you hear, the more you appreciate the size of this FRAUD. These lying & fraudulent people (Labor & VIC goverment included) are making the lives of those people, who live anyware near these industrial wind turbines, unbearable.

    The economics of these industrial wind turbines don’t stack up either, as they are stealing our hard earned money, in the way of electricity prices that are going sky high.

    All these wonderfull & bright ideas of Labor & the Greens are not going to make any difference to the planet, but are destroying peoples health & way of life.

Trackbacks

  1. […] top acoustic experts, including one of the most respected acoustic experts in Australia – Professor Colin Hansen.  It was also berated by crack neuro-physiologist, Professor Alec […]

  2. […] find out soon enough – crack operators, Steve Cooper and Prof Colin Hansen had that same place bristling with their state-of-the-art kit, at the same time. STT calls it […]

  3. […] top acoustic experts, including one of the most respected acoustic experts in Australia – Professor Colin Hansen.  It was also berated by crack neuro-physiologist, Professor Alec […]

  4. […] Health Department document referred to has been thoroughly canned by top acousticians, including Professor Colin Hansen and Alec […]

  5. […] complete pile of dross. As we reported a while back – world beating acoustic engineer – Professor Colin Hansen dumped a huge bucket on […]

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