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Understanding the Evidence: Wind Turbine Noise. The expert panel on wind turbine noise and human health
Abstract
In response to growing public concern about the potential health effects of wind turbine noise, the Government of Canada, through the Minister of Health (the Sponsor), asked the Council of Canadian Academies (the Council) to conduct an assessment of the question:
Is there evidence to support a causal association between
... Despite this fact, wind turbines noise is considered one of the main adverse aspect against the installation of wind turbines. The annoyance is the most common and most studied effect of noise on individuals [16], it can be defined as " a feeling of displeasure evoked by a noise " and " any feeling of resentment, displeasure, discomfort and irritation occurring when a noise intrudes into someone's thoughts and moods or interferes with activity " [17] The first studies which have investigated the relationship between wind turbine noise levels and the noise annoyance date back the 90s [18,19]. However, they were focused on wind turbines which sizes and heights were largely replaced over the years with the introduction of modern wind turbines. ...
Sin dai tempi antichi l'uomo ha costruito macchine che, sfruttando l'energia del vento, lo hanno aiutato a nutrire se stesso, la terra e a svolgere lavorazioni complesse. Con la scoperta dell'elettricità la funzione di queste macchine è cambiata radicalmente. Negli ultimi venti anni, politiche d'incentivazione hanno portato allo sviluppo di impianti eolici ed alla loro diffusione sul territorio, determinando una interazione sempre più intensa fra turbine eoliche, ambiente circostante ed uomo. Questo articolo presentata una rassegna dei principali fattori che determinano o modificano la percezione dell'impatto che queste macchine hanno sull'uomo e sull'ambiente circostante.
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Since ancient times the man has built machines which exploiting the energy of the wind have helped to feed himself, the land and carry out complex operations. With the discovery of electricity the function of these machines is changed radically. In the last twenty years, incentive policies have led to the development of wind farms and their diffusion over the territory, resulting in a more intense interaction between wind turbines, environment and man. This article presents a review of the main factors that determine or affect the perception of the impact that these machines have on humans and the surrounding environment. Parole chiave: turbine eoliche; impatto ambientale; disturbo da rumore, visione, moderatori
In response to growing concerns about the impact of excessive AM on residents, WSP | Parsons Brinckerhoff was commissioned by the Department of Energy and Climate Change to undertake a review of research into the effects of and response to AM and, if considered necessary, to recommend a control method suitable for use as part of the planning regime.
The aims of the study are to review the evidence on the effects of AM in relation to wind turbines, the robustness of relevant research into AM, and to recommend how excessive AM might be controlled through the use of a planning condition, taking into account the current policy context of wind turbine noise. The work included working closely with the Institute of Acoustics’ AM Working Group, who have proposed a robust metric and methodology for quantifying and assessing the level of AM in a sample of wind turbine noise data.
The study has involved the collation and critical review of relevant literature on the subject of AM, which included published papers on dose response studies, case studies, existing planning conditions, and current planning guidance. Key points from the reviewed evidence have been extracted and summarised upon which to draw the reports’ conclusions.
The review has concluded that there is sufficient robust evidence that excessive AM leads to increased annoyance from wind turbine noise, and that it should be controlled using suitable planning conditions. Key elements required to formulate such a condition have been recommended.
Thresholds of hearing Were determined in pressure field at frequencies from 4 Hz to 125 Hz. At the frequencies 4–25 Hz hearing thresholds were found that are in the lower middle of the range already reported by other investigators.
At frequencies from 25 Hz to 1 kHz thresholds have already been determined in free field by the same method and using the same subjects. The two investigations overlap at frequencies from 25 Hz to 125 Hz, and in this range the results were almost identical. The differences were below 1 dB, except at 63 Hz where the difference was 2.5 dB. None of the differences was significant in a t-test.
This study examines the relationship between indoor sound pressure level, local weather conditions, wind farm output power and resident rated annoyance in homes near a wind farm. A new methodology is presented that simultaneously records resident rated annoyance and corresponding time-series noise data while continuously monitoring one-third octave band noise levels and local weather conditions. Results of indoor noise and annoyance monitoring are presented for two homes near a wind farm whose residents claim to be annoyed by wind farm noise. Annoyance was found to be related to the overall noise level; however, noise levels were more strongly controlled by local wind speed.
An emerging environmental health issue relates to potential ill-effects of wind turbine noise. There have been numerous suggestions that the low-frequency acoustic components in wind turbine signals can cause symptoms associated with vestibular system disorders, namely vertigo, nausea, and nystagmus. This constellation of symptoms has been labeled as Wind Turbine Syndrome, and has been identified in case studies of individuals living close to wind farms. This review discusses whether it is biologically plausible for the turbine noise to stimulate the vestibular parts of the inner ear and, by extension, cause Wind Turbine Syndrome. We consider the sound levels that can activate the semicircular canals or otolith end organs in normal subjects, as well as in those with preexisting conditions known to lower vestibular threshold to sound stimulation.
To clarify the process and emergence of the effects of infrasonic noise on man, the sound pressure level of infrasonic noise was measured in the area along a superhighway, and its effect on the inhabitants was investigated by the questionnaire method. The results are as follows: (1) The main component frequency of the infrasonic noise was 6.3 Hz. The sound pressure level (L50) of infrasonic noise (1–50 Hz) showed more than 85 dB in the daytime and more than 72 dB in the night time. It's peak level was above 100 dB under the overhead bridge of the superhighway. Indoors, the sound pressure level (L5) of infrasonic noise often went above 75 dB. (2) Answers about the living environment were given by 368 (85.6%) out of 430 families. Those about the condition of health were given by 909 cases (81.7%) out of 1113 cases who were all the inhabitants over 15 years of age. (3) 69.6% of families complained of the shaking of windows and the like. 65.8% of families complained of window rattling. More families complained of the shaking and rattling of windows in the area less than 80m distant from the superhighway, and more families also complained of the disturbance of sleep in that area. (4) The rates of the complaints as to ‘irritating’, have headaches', ‘head feels heavy’, ‘pain in arms or legs’, ‘feel languid’, ‘sleepless’, ‘dizziness’, ‘ringing in the ear’, and ‘difficulty in breathing’, were correlated with the distance from the superhighway. While the rate of complaints as to ‘have stiffness or pain on shoulders’ was highest, it had no relationship with the distance from the superhighway.
From these results, it can be concluded that the inhabitants first complained of the shaking and rattling of windows by infrasonic noise, and then became chronically insomniac and excessively wearied by shaking and rattling of long continuance, and finally became highly sensitive to infrasonic noise. This increasing sensitivity might be closely connected with the emergence of the effect of infrasonic noise upon these inhabitants.
This paper presents a general overview of wind turbine noise including sources, measurements standards, psychoacoustics, infrasound, propagation and regulatory perspectives. The authors presented similar material at the National Wind Coordinating Committee's special meeting on "Technical Considerations in Siting Wind Developments" [1] held in Washington D.C. In addition, many relevant papers can be found in the proceedings of the First International Conference on Wind Turbine Noise 2005 [2], some of which are summarized here.
There is a substantial need to find a balanced approach to deal with people’s concern about wind turbine effects. Indeed, the psychological factors that affect community response will be an important facet in this complete agenda development. Many of these relevant issues are related to the soundscape concept which was adopted as an approach to provide a more holistic evaluation of “noise” and its effects on the quality of life. Moreover, the soundscape technique uses a variety of investigation techniques, taxonomy and measurement methods. This is a necessary protocol to approach a subject or phenomenon, to improve the validity of the research or design outcome and to reduce the uncertainty of relying only on one approach. This presentation will use recent data improving the understanding about the role of psychoacoustic parameters going beyond equivalent continuous sound level in wind turbine affects in order to discuss relevant psychological factors based on soundscape techniques.
An experiment was conducted to measure and characterize infrasound (and higher frequency acoustic energy) from turbines at a wind farm in Southern Alberta. Simultaneous telemetry and point measurements were acquired from three sensor types: low frequency geophones, acoustic microphones, and a precision sound analyzer. Measurements were recorded for three wind states: low, medium, and high. Down wind telemetry measurements were recorded for thirty (30) continuous 50m offsets, up to a distance of 1450 m from the wind farm. Point measurements, coincident with the telemetry measurements, were acquired with a low frequency precision sound analyzer for two offsets: 50m and 1000m from the turbines. The same measurements were recorded with the turbines on, and with the turbines off. The low frequency results of the experiment are presented in this paper.