I have been immersed in acoustics all of my professional life. My experience includes noise control, performance halls, houses of worship and speech communication in noise. A disability has slowed me up in recent years, but I have read nearly all of the reports and letters regarding Wind 1. Some of my colleagues have acted as consultants on this project and on occasion we have discussed the findings.
Fifty years ago there was not much known about quantifying hearing damage due to noise. A very large data collection process with intelligent analysis
led Karl D. Kryter to author the seminal book synthesizing the subject, “The Effects of Noise on Man.” The first noise regulation in the US was in 1975 in Portland, Oregon. From then on noise became an environmental issue rather than just a “nuisance.”
Now we have a potentially serious noise problem with Wind 1. An even larger problem we have as acoustic engineers is that there is no metric for evaluating disturbance due to infrasonic modulated noise—at least not yet. In fact, there is not even an instrument that can accurately measure the radiated acoustic and vibration field from slow-moving turbine blades. Falmouth is not alone, as there is a lot of attention being paid to the problem in the UK, Canada and the EU.
The worst thing we can do is to ignore the affected people. They are a point on a curve yet to be drawn. Looking back at the history of hearing damage, I can see many points shaping the curves we use to evaluate and predict industrial noise exposure. I personally delivered a hearing protector to a machinist who complained about the noise in an unforgettable way—his family life was coming apart. He agreed to wear them faithfully every time he ran the machine and a week later, after interviewing him again, I was astonished and pleased. Another point on the curve.
Noise regulations in effect now do not encompass turbine noise as a physiological or psychological disturbance. I see a statement that “…it does not violate the state regulation for environmental noise…” Okay, agreed. What instrument was used? A standard calibrated type 1 sound level meter, of course, exactly to state or local requirements. My reaction is, “Why don’t you come back when there is a new regulation and an instrument capable of evaluating what these unfortunate neighbors are feeling and reporting?”
There is a new institute formed at the University of Waterloo in Ontario on exactly this subject, and Dr. Nina Pierpont of Johns Hopkins Medical School has written in Counter Punch Magazine: “…The vestibular organs—the semicircular canals, saccule, and utricle—function as Mother Nature’s gyroscope, controlling our sense of motion, position, and balance, including our spa- tial thinking. (Remember when you got carsick as a kid? Or sea-sick?) “Humans share these enigmatic organs with a host of other backboned species, including fish and amphibians. Some scientists indeed see them as a kind of pan-species master key for an extraordinarily broad range of brain function—amounting to a sixth sense. “One of those functions, it now appears, is to register and respond to the sounds and vibrations (infrasound) we don’t consciously hear, but feel – as from wind turbines. For many people, the response is swift and disastrous.”
The last line says it all—what you can’t hear can hurt you—stop talking around the subject, mitigate as required to the comfort of the neighbors, and wait for more points to get the curve right.
Richard H. Campbell,
FASA, FAES, NCAC