Cooper, S. Cape Bridgewater Public Meeting – Answers to Written Questions

Written Questions

Written questions were provided to Pacific Hydro

In view of the number of questions, Pacific Hydro have grouped them into different categories.

A number of the questions have been answered in full or in part in the first part of tonight’s presentation.

(All charts and graphs available at the downloadable document at the bottom of this page.)



  • (1) Did you ask Pacific Hydro to engage other residents in the study who were also living near the Cape Bridgewater wind farm and did not feel as affected by it? This may have allowed you to test infrasound levels at those other properties, so you could help decipher if the three properties experienced higher infrasound levels than other properties in the area, yes?
  • (2) If this study was not a health study, why did you get participants to record symptoms they experience? And tell The Australian that there was something related to health effects in what you had found?
  • (3) Was balance exercise testing within the scope of the work you were asked to do? Were you aware of any health impacts that may arise from carrying this out, and did you inform the participants of these? One participant wrote in their personal report on the study that they felt “intense sickness and headache” for 3 1/2 hours after carrying out the test. Did you consider what impact that “exercise” may have on the health of the subjects before you carried that out? If so, did you have any measures in place to mitigate that impact, such as a medical person available to treat them? – Do you consider that balance exercise to be audio testing?

On page 164 of the study it is stated: 

As noted above the bending exercise is not part of the acoustic study but arose from observations and discussions with the residents during the course of the study when in one instance a resident bending over to open a gate experienced an immediate and noticeable increase in sensation in the head. This information is provided at the request of the residents for the benefit of other researchers. 

  • (4) Did residents know when the wind farm was shut down?

A-weighted levels – noise testing

  • (5) The Report says that dB(A) is of no value, and on that basis there is no difference between ON and OFF. Please provide examples of that and then discuss how the Permit conditions can accurately define Acoustic Compliance. Please explain why there is no assessment of the Compliance of the Wind Farm?
  • (6) How do you determine acoustic compliance of a wind farm? If as your Report indicates, you cannot determine the A weighted value? I understand there is a difference between contribution and measured level. By reference to your Report, please explain the differences?

On-Off testing – Wind turbine signature concept

  •  (7) I have seen the differences in the Infrasound levels when the turbines are operating and when they are off. Could Mr Cooper please show those differences in relation to House 89?
  • (8) After considering all different acoustic perimeters that simply did not work, you utilised the narrowband analysis and developed a concept dB(WTS). Could you provide for one of the SHUTDOWNS a graph of the dB(WTS) ?
  • (9) The on-off testing clearly shows the (WTS) signature to be coming from the turbines. Can you please explain why 1/3 octave band results show no difference whereas narrow band results do show a difference?

Wind turbine signature – sensations ‘trend’ finding

  • (10) At the Community Consultative Meetings in Cape Bridgewater you have explained the methodology lining up patterns, reactions and observations to identify wind farm operations that gave rise to the highest level of sensation. Would you please explain that procedure to the people present here, who were not at the community consultative meetings in Cape Bridgewater.

  • (11) If drug company conducted a trial on 100 patients, and then only followed up with 6 of the patients to assess their reactions to the drug, one would imagine the study would have little or no credibility. Of the 552 physiological experience reports collated in your study, you state on page 115 that you only analysed 31 of them primarily due to insufficient time to perform the analysis. Do you think this methodology would successfully pass through a peer-review process?
  • (12) In Figures 49 and 50, with the ‘sensation 5’ vs. Wind Turbine Signature’ relationship is based on just 6% of the data collected, therefore can these results be considered valid on a scientific basis?
  • (13) How can you draw any conclusions when you base your final report analysis on only 5 per cent of the sensations diarised by the residents, or 31 reports, of people feeling ‘sensations’? This is a very small percentage of the material you had available, and is very, very selective, yes?
  • (14) Sensation 5 is an extreme level of disturbance which we too experience on a regular basis. The Report utilises the extreme or unacceptable situation of Sensation 5 to determine a new perimeter. There has been adverse comment as to why Sensation 4 was not assessed. Could you clarify why Sensation 4 was not used, if it is relevant, noting that the Report indicates a large amount of time would be required to process the Data. To enlighten us could you advise what are the steps in undertaking the process and analysing the Data?
  • (15) If as Pacific Hydro claims there is no correlation of Noise or Vibration from the Wind Farm, but there is a trend of sensation versus the Wind Farm, what is the difference between correlation and trend?
  • (16) According to the appendices of the report, the residents reported a very large number of noise, vibration and physiological complaints during extremely low wind speeds and the shutdown period— both instances when the wind turbines were not operational. If residents were reporting noise, vibration and physiological impacts during times of low and shutdown, how can it be possible to determine any linkage between diary entries and wind farm operation?
  • (17) You attributed recorded ‘sensations’ that the 6 residents felt to both moving, and stationary wind turbines (ie. when the turbines have been turned off). If the sensations can be detected at both times (on and off), how do we know the turbines are the cause of these sensations at all? This conclusion is unfalsifiable, isn’t it?
  • (18) You told The Australian some of these sensations were recorded when the turbines were switched off, but that the sensations were being experienced when there were strong wind gusts, causing the stationary towers to vibrate. However, some of these sensations were recorded when there were low wind speeds. Can you explain the latter reporting of high sensation, then?
  • (19) How does your “sensation” and dB(WTS) work here at Cape Bridgewater relate to measurements you did at Waterloo (concurrent with the 2013 SA EPA Waterloo Noise study) and noise diaries provided by the residents at the SA EPA sites?
  • (20) On reading your report I find that the brief was very specific to investigating specific local residents complaints. I see that you were required to determine certain wind speeds and certain sound levels that related to disturbances reported by the residents. There has been adverse comments about the conduct of the study that would appear to originate from persons not having actually read the study. I see that sensation covers what residents actually experience. Your report does not identify what the residents noted as to their experiences during the study but kept it in the severity ranking set out in the instructions for the survey. My question is that whilst you have protected the residents observations from being given to anybody outside of your office, from the diaries can you confirm that the residents reported sleep disturbance, nausea, headaches etc when sensation 5 was experienced?
  • (21) The definition of Sensation covers a range of feelings or experiences. The report indicates all residents noted experiences of sensation. Therefore it follows that at the worst sensation levels of 4 and 5 involving those adverse impacts, our health and quality of life is affected. Whilst the report is an Acoustic Measurement Study is it not correct that it also indicates by definition, people’s health is being affected? The report identified sensation as resulting in impacts we feel that significantly affect our quality of life. Sensation 5 is clearly an unacceptable impact with the sensation of having to leave our homes immediately. To be consistent with general environmental acoustics where the aim is to protect residents 90% of the time, what sensation level on the measuring scale used in this study is consistent with that aim? I think you have said it is sensation 2 but I would like to clarify that.
  • (22) We are the residents of House 87 referred in the Steven Cooper noise report. We understand the three homes in this study were subject to different exposure levels dependent upon the relative height/shadow zone of infrasound generated by the turbines. Could you please explain the shadow zones?
  • (23) Were the wind farms audible at the complainants’ houses? So if audible, could you have described a correlation between audible noise and distress?
  • (24) The participants in your study published a press release on an anti-wind group website, in which they state “Our diaries and the concurrent full spectrum acoustic measurements inside and outside our homes clearly demonstrate that it is the operation of the wind facility correlating with our symptoms”. According an article in The Australian, you are quoted as declaring a ‘cause and effect’ relationship between wind turbine operation and health impacts. Do the contents of your study agree with your quotations in The Australian, or the media release from the residents?

The Australian on 21 January 2015 indicates that I had said: 

Mr Cooper said it was the first time that sensation rather than audible noise had been used as an indicator of residents’ perception of nearby wind turbines. 

Mr Cooper said the findings were consistent with research into health impacts from early model wind turbines conducted in the US more than 20 years ago. 

Mr Cooper said the findings had totally discounted the so-called “nocebo” effect put forward by some public health officials, who said symptoms were the result of concerns about the possibility of experiencing them. 

Mr Cooper said residents’ threshold of sensations were experienced at narrow band sound pressure levels of four to five hertz at above 50 decibels. 

Mr Cooper said an earlier investigation into health impacts of wind farms by the South Australian EPA had been flawed by limiting the study to only one-third octave bands and not looking at narrow band analysis. 

“By looking at high sensation and narrow band I have developed a methodology to undertake assessments using narrow band infrasound. We now have a basis on how to start the medical studies” he said. 

Mr Cooper said Pacific Hydro should be commended for allowing the work to proceed.

“It is the first time ever in the world that a wind farm has co-operated with a study including shutting down its operations completely,” he said.

The following day the Australian ran another article. 

Attributed to Mr Marsh is the quote:

Noise measurements had been taken at just three houses and a small number of self-nominated people participated who had previously made complaints about the wind farm’s operation,” Mr Marsh said.

 He said the report’s author, acoustics expert Steven Cooper, “believes he has discovered a link between ‘sensations’ felt by the participants and the operation of the wind turbines”. 

“However, a number of these ‘sensations’ were reported when the wind turbines were not operating,” Mr Marsh said.

What was attributed to me was:

Mr Cooper said wind farm owner Pacific Hydro had limited the study to three houses and the brief was to measure noise and vibration and see if the complaints from residents could be related to specific wind conditions or noise levels. 

The study was required to work backwards from the resident’s observations and see what wind or noise levels agreed with the complaint,” Mr Cooper said. “I don’t think you can get any more objective than that.”

Mr Cooper said simple monitoring of each house had cost about $40,000 and complex monitoring with multiple microphones and vibration detectors was $100,000. On-site monitoring of the turbines had cost a further $40,000.

Some sensations and vibration impact had been reported when the turbines were not operating. But Mr Cooper said this was due to vibration of the blades and towers when they were subjected to wind gusts.

On 23 January The Australian ran another article “Noise specialist cheers wind farm report” 

The “quotes” provided are: 

In his report, Mr Cooper said the residents’ observations “indicates that the major source of complaint from the operation of the turbines would appear to be related to sensation rather than noise or vibration”. 

Mr Cooper said the results were in line with studies in the US on early-model wind turbines and appeared to be the result of instability of the turbine blades, which did not have free air flowing over them. 

Due to the small number of residents surveyed, Mr Cooper and the company said, more testing was required. 

Pacific Hydro has said that it did not accept Mr Cooper’s findings that a “cause and effect” had been established between wind-farm performance and resident complaints. 

So the actual facts are that I never said or was I quoted in The Australian as declaring a “cause and effect’ relationship. Pacific Hydro made the quote that appears in The Australian. A global search of my report could not find the phrase “cause and effect”.


  • (25) One statement published in the Portland Observer by the study participants said “our diaries and the concurrent full spectrum acoustic measurements inside and outside our homes clearly demonstrate that it is the operation of the wind facility correlating with our symptoms.” (23/1/15) What is your comment on that statement as it relates to your report? Is there a correlation?)
  • (26) Your ‘multi-channel acquisition’ system, with which you measure your ‘wind turbine signature’, was, as you state in your report on Page 27, only at an occupied house for four nights out of an eight week study period. This is only 7% of the period, and it is these four nights on which your major conclusions are based. Is this enough data to state conclusively, as you have in an article in The Australian, that there is a cause and effect relationship between physiological symptoms and the operation of the wind farm?

Findings or conclusions of the report 

  • (27) It is common practice in scientific studies to use measures of statistical significance when determining correlations and causal relationships. Why did you choose to reject any measure of statistical significance in this study? Would you be willing to make full data sets available, to enable others to perform statistical tests on your data?
  • (28) It is noted from the study that all the low frequency and infrasound measurements were found to be below the recognized human thresholds of perception, therefore how could the residents be ‘sensing’ the emissions from the wind turbines?
  • (29) As the level of ‘unacceptable presence of sensation’ inside a dwelling is specific only to the residents in question, according their subjective observations – therefore is it true that the use of Wind Turbine Signature could never be extrapolated beyond the specific individuals involved in determining it?
  • (30) A study released by Health Canada a few months ago found no link between wind turbine operation and human health impacts. It involved 1,238 residences, 4,000 hours of acoustic data, objective and subjective health measures, a peer-reviewed published methodology, measures of statistical significance, a randomly selected sample, 17 different wind turbine models, two provinces, 24 government, academic and industry experts and 4 international advisors. Are you aware of this study, and would you say that your report is of higher or lower scientific accuracy than the Health Canada research?

Questions pertaining to current or future noise guidelines or regulations

  • (31) Could Professor Cooper expand on the inadequacies of the arguments on which the current noise guidelines are based?

  • (33) The significant effects of turbines of this size are very concerning and no doubt very problematic for the residents of Cape Bridgewater and those living near other wind projects. New regulations now allow turbines to be built to any size. How do you think these effects will change when turbines are, for example, 4 or 5 MW and 200 metres high or even larger? 
  • (34) The on-off testing clearly shows the (WTS) signature to be coming from the turbines. Does this have implications for changes to international turbine noise measurement standards especially given that the current standards were created nearly 2 decades ago?
  • (35) As a Cape Bridgewater resident of House 87 I ask the following: From your report can you derive a separation distance for wind turbines from homes based on sensation? For our three homes which were the subject of this study, what should those separation distances be? Given the severity of your findings from the testing at Cape Bridgewater would you accept that living permanently exposed to the reported conditions is a hazard?
  • (36) Do you think your study’s results justify a change in Victorian noise pollution guidelines?
  • (38) By the use of dB(WTS) obtained in the study can you predict or calculate a separation distance which will agree or approximate with Sensation 2? If so, please provide an example.

Response to report

  • (39) Mr Cooper’s Acoustic Report identifies the specific brief for the Project yet Press Statements by the Wind Industry referred to a different type of Study. WHY? Please explain.

Next steps or further study

  •  (43) In view of the results of Mr Coopers study with a small specific number of impacted residents, would it be possible for him to comment on the idea that a wider assessment in terms of a larger area/ number of turbines /residents re the Wind Turbine Signature is likely to produce a more comprehensive result especially related to the topography of the area out to 5 km and 10 km.

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