Tech Environmental e-Newsletter
December 2010


At this very moment, you are enveloped in naturally occurring infrasound, which is inaudible.  Infrasound is always present in the outdoor environment due to sounds generated by air turbulence, meteors, waves at the shoreline, motor vehicle traffic, distant aircraft, ventilating fans, and other machines that are part of our modern world.

Recently, wind turbine opponents have begun raising awareness of infrasound, citing it as a public health threat posed by wind turbines. One piece of evidence that is often employed is a NASA study from the 1960s, in which test subjects were stood next to a large jet engine. However, that study focused on infrasound levels up to 150 dB, energy levels 100 million times the level of infrasound that a community would experience from a wind turbine. Wind energy opponents nonetheless believe that wind turbines would have harmful infrasonic effects on people who live nearby.

Measured infrasound levels near the shoreline on Cape Cod and Nantucket reveal natural levels of 70 to 82 dB when winds are offshore and 78 to 89 dB when winds are onshore. Rural sites with open fields have levels averaging 71 dB. Wind turbines have been shown to produce infrasound less than 70 dB. Meanwhile, the U.S. Food and Drug Administration approved the use of infrasound at 70 dB as a safe massage therapy.  A pianist playing a low A-major chord encounters infrasound at 63 dB. Since the human hearing threshold at this frequency is 90 dB, all of these examples of infrasound are inaudible.

A comprehensive study by British acoustician Dr. Geoff Leventhall concluded that infrasound from wind turbinesdoes not pose a threat to public health. In addition, EPA has concluded that there is no scientific evidence that infrasound below the hearing threshold produces any human health effects, physiological or psychological. Thus, infrasound from wind energy projects is lower than natural background levels; it is inaudible, and it has no effect on people.

Tech Environmental helps wind power proponents and communities hosting wind power projects study and evaluate potential acoustic impacts from wind turbines. We have worked on 41 wind energy projects, many of which can be viewed on our website or via PDF. For more information on Tech's acoustic services, contact Peter Guldberg at

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Tech Environmental would like to send our warmest holiday greetings to all of our clients and friends.

Thanks for your support in 2010, and we hope for a healthy and happy 2011 for everyone!



The founder of Tech Environmental,
Peter H. Guldberg, CCM, has over 35 years of experience as an air quality and noise consultant, providing solutions to potential impacts from energy, transportation, and industrial sources.


Mr. Guldberg has managed dozens of wind energy projects [PDF], overseeing monitoring, modeling and mitigation, providing expert testimony and answering questions from the public. In addition, Mr. Guldberg served on the Massachusetts Governor's technical advisory committee for the development of greenhouse gas policies.

Mr. Guldberg has prepared acoustic analyses for dozens of wind power projects, including the Cape Wind Project.

As a Certified Consulting Meteorologist(CCM), he has taught air pollution permitting and assessment to over 1,400 regulators, consultants, and clients.  He has also been involved in hundreds of public hearings and legal proceedings regarding air quality, odor, noise, and dust concerns. He can be contacted at



303 Wyman Street, Suite 295

Waltham, Massachusetts 02451

ph. 781-890-2220

fax 781-890-9451



TECH ENVIRONMENTAL, INC. specializes in finding real solutions to air quality, odor control, noise and vibration, fugitive dust, and health & safety challenges. Our focused knowledge in air-quality-related fields is enhanced by a comprehensive understanding of environmental regulations and technologies. Visit our website at or contact us by phone at (781) 890-2220.