Infrasonic noise not considered

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Dear editor,
RE: Stacey Reid’s letter on noise and turbines (Vacuum is louder than a turbine, June 28).
Developers and our government will state that the maximum allowable limit of wind turbine noise is 40 decibels; however ministry guidelines allow the noise levels to increase from 40 dBa to 51 dBa under increased wind conditions.


A 10 decibel increase in noise is perceived as a doubling of sound to the human ear. Noise coming from wind turbines does not match the sound of a refrigerator or a quiet library as we so often hear. Under most circumstances loud noise is short term that will pass by, can be turned down or shut off.

With wind projects none of the above applies.  The dynamics of living surrounded by multiple turbines cannot be compared to other community noises.
The noise is not only loud, it is cyclical in nature and there is no ability to turn it down or shut it off at two in the morning when families cannot sleep. The audible noise problem is compounded by the presence of low frequency noise. This is noise you cannot hear but you can feel. It penetrates walls.

This combination can keep people awake part of the night, or in some severe cases all night, on an ongoing basis. There is no reprieve and in some cases they have no choice but to abandon their home.

It is known that many of these wind projects are operating with noise levels that are out of compliance, exceeding even the maximum 51 dBa noise level allowed. The general public is unaware of this because the ministry has chosen to leave wind projects out of the traditional checks and balances that other industry must abide by.

Wind turbines and transformer stations must have a Certificate of Approval to operate. If they are operating out of compliance, there should be some record of contravention of the approval, but oddly there are no contraventions listed on the ministry’s annual reports from any wind developer even with documented exceedances in hand.

It is no wonder the public is confused. This provincial government is doing a grand job of it.

Barbara Ashbee, Orangeville

Orangeville Banner

Stacey Reid’s letter (Vacuum is louder than a turbine, June 28) shows a misunderstanding of what a “dB” is and how it is measured, which leads to easy acceptance of the “noise, what noise?” position of wind farm proponents.  A “dB” is a decibel — a measure of sound energy of any range — perhaps speech, bass speakers, vacuum cleaner noise or an earthquake. Our ears hear a only certain range of that energy — call it the “middle” range, including bagpipes, arguing couples and vacuum cleaners.

Community noise standards are based on sounds in the middle range, mainly because they are enforceable with inexpensive and easy-to-operate sound level meters. In sound measurement, this is called the “A” range and the measurements should read “dBA.”

Above and below that range, progressively, we hear little or nothing. Bats squeak in the “high” range. In the “low” range, we feel bass as well as hear it — it may nauseate us if it’s too loud.

Noise complaints about bass are more difficult to administer than sounds in the “A” range, as many communities have found, because they don’t necessarily show up on the sound meter.

But what about wind turbines? The majority of the noise they make is in the deepest “infrasonic” range, measured as “lin” — below bass, below hearing — and only measurable with expensive equipment by trained technicians. A study by NASA shows that the infrasonic part of the noise of turbines is about 55dB louder than the “A” part that a conventional meter would display.

So, if the meter reads 40dBA, the infrasonic noise can be 95dB. Although inaudible, this noise is experienced by the body in other ways that may be more akin to a continuous earthquake than to a refrigerator.

The doctors will have to weigh in on the health effects of these inaudible sound energies at strong levels over continuous periods of time, but the reference to community standards excludes the more relevant facts.

By comparison, although we can’t see the UV range of sunlight, we’ve learned the consequences of exposure and take precautions accordingly.

Dave Clark, Shelburne

7 thoughts on “Infrasonic noise not considered

  1. Infrasonic sonar is harmful and disruptive to whales. Probably other species too.

    Who knows what effect the steady subsonic drone of windmills has on species living in the earth?

  2. > Who knows what effect the steady subsonic drone of windmills has on species living in the earth?

    From time to time, I look for studies on responses of fish to infrasound. In doing so, I come across studies on invertebrates, birds and other creatures. The information seems new and patchy, which makes me especially grateful for the offshore moratorium in Ontario waters of the Great Lakes. There’s much we don’t know. There seems to be more info on marine animals than freshwater, and researchers often are looking to bar animal access from water intakes, say, or to look at effects of anthropogenic sound on natural systems, or to understand migration, navigation, or predator-prey interactions.

    Sensitive species include
    spruce grouse (display drummers),
    homing pigeons (navigation),
    European eels (American Eel is a migratory, at-risk species),
    carp & minnows (belong to subgroup of fishes in which tiny bones link inner ear & swim bladder), coral larvae (they “hear” reefs to settle on), and
    snakes (leave dens in anticipation of earthquakes).

  3. docs.wind-watch.org/buxton-infrasoundandlandbasedanimals.doc

  4. that comparison to uv rays, just made all the sense in the world to little o’le me.

    Now I can explain infra sonic.

    Thanks for that.

  5. Considering the effects of wind turbine noise without considering the unheard infrasound component is really like:
    1) considering sunlight exposure while ignoring the effects of ultraviolet light.
    2) considering a codeine/tylenol drug overdose while ignoring the codeine dose.
    3) considering the effects of a tsunami, but ignoring cases of drowning.
    4) considering traffic deaths, but ignoring deaths on motorcycles.
    5) considering global warming, but ignoring the effect of carbon dioxide.
    6) considering heart disease, but ignoring the effect of trans-fats
    I could keep going…………….
    It just doesn’t make sense 🙂

    • Loved the 50p PPT presentation to Washington U Dept of Otolaryngology, May 6, 2011! Please, if possible, consider giving the presentation to a wider audience via webinar.

      *Alec N. Salt, May 6, 2011. Can the Sound Generated by Modern Wind Turbines
      Affect the Health of Those Living Nearby? Presentation to Washington U Dept of Otolaryngology.
      http://oto2.wustl.edu/cochlea/WashUMay2011.pdf (Accessed July 8, 2011)

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