Resource Documents: Noise (576 items)
Documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are provided to assist anyone wishing to research the issue of industrial wind power and the impacts of its development. The information should be evaluated by each reader to come to their own conclusions about the many areas of debate.
Author: Stiller, Thomas
“Ich fühle, was Du nicht hören kannst.” So beschreiben Anwohner gerade von Windkraftanlagen oft ihre Beschwerden, ausgelöst durch niederfrequente Geräusche (Infraschall). Aber was ist die Ursache von Infraschall, welche Auswirkungen hat er auf Menschen, welche Normen regeln die erlaubten Schallemissionen und was ist der Stand der Wissenschaft auf diese Fragen? … Die niederfrequenten Schwingungen aus Kompressoren und Windkraftanlagen erzeugen bei diesen Menschen Stressreaktionen, die sich u.a. in Schlafstörungen, Konzentrationsstörungen, Übelkeit, Tinnitus, Sehstörungen, Schwindel, Herzrhythmusstörungen, Müdigkeit, Depressionen und Angsterkrankungen, Ohrenschmerzen und dauerhaften Hörstörungen äußern.
Inaudible but biophysiologically effective sound is not science fiction but an increasing threat to health. First, a few physical bases: sound is the pressure change in a medium such as air and spreads around the source. The lower the frequency, the more sound is transported in the air. Very low frequencies are also transmitted through closed buildings. As a result of acoustic reflections and superimpositions, it can then lead to excessively high sound pressure values. In general, sounds and noises are described by frequency, timbre and volume. The human ear can hear frequencies approximately in the range of 20,000 Hz, i.e., vibrations per second (high tones) to 20 Hz (low tones). The sound range above a frequency of 20,000 Hz is referred to as ultrasound, below 200 Hz as low-frequency sound, below 20 Hz as infrasound. Both infrasound and ultrasound are no longer perceived by the ear, but the body has a subtle perception for infrasound, and some people are particularly sensitive to low-frequency sound.
In nature, low-frequency vibrations are ubiquitous. For example, some migratory birds orient themselves by the noise of the sea which is transmitted over several hundred kilometres in the atmosphere. The infrasound from wind turbines is still measurable for several kilometres. …
About 10-30 percent of the population is sensitive to infrasound radiation. These people, which in Germany number several million, develop numerous symptoms, which are now understood by more and more physicians. The low-frequency oscillations from compressors and wind power plants cause stress reactions in these people, which manifest themselves in sleep disorders, concentration disorders, nausea, tinnitus, dysphasia, dizziness, cardiac arrhythmia, fatigue, depression and anxiety disorders, earaches and permanent hearing impairments. …
Author: Rand, Robert
Differential acoustic pressure measurements were acquired and logged at three homes in the vicinity of the Golden West Wind Facility in El Paso County, Colorado during December 2015 and January 2016. A week of data was analyzed for each of the three homes and daily spectrograms produced which are attached. Each day’s data consisted of approximately 4.3 million differential pressure samples with a week comprised of some 30.5 million samples.
Preliminary investigation confirmed the presence of recurring acoustic pressure oscillations at 0.2 to 0.85 Hz (the “blade pass frequency” or BPF) which are associated to the Golden West wind turbine rotations. At times multiple oscillation frequencies were observed, consistent with multiple turbines operating at different rotation rates. Oscillations appeared to be more pronounced when the turbines are more upwind rather than downwind. Neighbors reported they are mostly downwind due to turbine location relative to home location and for the prevailing winds in the region.
Typical BPF total acoustic power were computed for example portions of the differential pressure data sets. Crest factors (the ratio of RMS to peak levels) were also computed for segments dominated by wind turbine rotation and uncontaminated by other noise, with typical crest factors of 13-19 dB. Totalized BPF RMS levels ranged from 56 to 70 dB re 20uPA, with peak levels from 71 to 89 dB. The RMS and peak levels are similar to those found at other sites with appeals to stop the noise, legal action, and homes abandoned.
It is understood from neighbors that they have experienced disturbance since the turbines started operating whereas prior to turbine operation there was no similar disturbance. It is understood that neighbors report improvement when turbines are shut down (not rotating) or when they remove themselves physically away from the Facility a distance of several miles.
El Paso County noise regulations define “Sound” as oscillations in pressure (or other physical parameter) at any frequency, and, prohibits noise disturbance due to acoustic oscillations.
The analysis is far from complete in that numerous segments of each day at each monitoring location could be analyzed and associated to journal entries and/or medical data. The reported association of proximity to the operating facility to disturbance in health and quality of life appears supported by the acoustic data acquired for this preliminary investigation. These preliminary investigations suggest that there is a condition of noise disturbance due to very low frequency acoustic pressure oscillations in the vicinity of the Golden West Wind Facility when it is operating, with more severe impacts downwind.
[NWW thanks Friends Against Wind for providing the video.]
Author: Ambrose, Stephen
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 …
Author: Ambrose, Stephen