There is an unsaid purpose and intent for this request [from the Vermont Public Service Board (PSB)]. Might it be an acknowledgement that “Vermont’s wind turbine noise rule does not protect neighbors from excessive noise and adverse health impacts”? This is obviously due to persistent complaints, and at least one home abandonment. This solicitation for public comments should not be used to divert-delay-deny public attention. Wind turbine neighbors want the PSB to correct the current flawed regulations based on accepting for regulatory rules those the wind industry recommends. If the PSB sought advice from truly independent sources they would have learned that 45 dBA is only applicable for urban-residential areas and even for those communities is not sufficient to protect people. Ontario, and other Canadian provinces have regulations setting 40 dBA as the not-to-exceed threshold. Yet, recent studies have shown strong evidence that 40 dBA is not preventing adverse health impacts. Even 40 dBA is too loud. Somehow the cautionary warnings of the 1970s about 35 dBA for quiet rural-residential environments have been ignored. Standards such as ISO 1996 and ANSI’s S12.9 still support 35 dBA for nighttime noise in quiet rural regions.
The noise rule needs a large scale reduction in its permitted noise limits to protect and minimize noise complaints. Anything less will only continue the endless discussions for equivocating with fudging, quibbling, and evading the need to lower to 35 dBA. Adding superfluous and complicated measurements, procedures or protocols around the 45 dBA will only continue to result in failure. The PSB should understand this after receiving reams of unfathomable data from acousticians closely aligned with developers that has no connection to a human response.
The PSB should seek assistance from independent experts to establish a noise rule that minimizes adverse human responses. This noise limit must be easy to understand and enforce. The PSB should not have to deal with the intricacies of acoustic science, noise sources, propagation, and weather. These are the concerns for the noise consultants who are responsible to their wind developer clients, who need to advise their clients on how not to harm the public. The PSB should focus on public health and enforcing compliance; and not be negotiating mitigating options with developers, operators, or consultants.
The current wind turbine sound rule should be abandoned and replaced with the previous noise limits. The Environmental Board used Lmax for its regulations and that has been upheld by the Vermont Supreme Court (see page 11). The Lmax refers to the instantaneous maximum level (LAmax) relative to the background (LA90). People hear the instantaneous variations above the background and respond accordingly, which cannot be substituted with a time-weighted average. Adverse public reactions are shown to occur when the Lmax exceeds the background L90 by 10 dB.
Answers for most of the questions start on the next page …
Download original document: “Proposal and comments for implementing a rule regarding sound from wind generation projects ”
See also: Vermont Public Service Board Sound Rule Workshop  (presentation)