Effects Of Wind Turbine Noise Research Articles

An analysis of self-reported sleep disturbance from nighttime wind turbine noise suggests minimal effects but highlights the need for standardization in research designa).

The World Health Organization Environmental Noise Guidelines provide source-based nighttime sound level (Lnight) recommendations. For non-aircraft sources, the recommended Lnight is where the absolute prevalence of high sleep disturbance (HSD) equals 3%. The Guideline Development Group did not provide an Lnight for wind turbines due to inadequate data. In the current study, calculated outdoor wind turbine Lnight levels ranged from <20.5 to 41.5 dB(A). Between May and September 2013, questionnaires were completed by 606 males and 632 females, 18-79 years of age, randomly selected from households 0.25 to 11.22 km from operational wind turbines. When the source of sleep disturbance was unspecified, the mean prevalence of HSD was 13.3% overall and unrelated to Lnight (p = 0.53). As Lnight increased, identifying wind turbines as one of the causes of HSD increased from 0% below 20.5 dB(A) to 3.8% between 35.5-41.5 dB(A) (p = 0.01). The 3%HSD benchmark was observed where Lnight was 33.5 dB(A) [95% confidence interval (CI) 31.1-36.1 dB(A)]. Results affirm findings from Health Canada's Community Noise and Health Study of minimal impacts of wind turbines on sleep [Michaud et al. (2016a). "Effects of wind turbine noise on self-reported and objective measures of sleep," Sleep 39(1), 97-109], yet noted uncertainties and limitations are discussed, including the suggestion that the HSD benchmark for wind turbines may be too low.

Effects of wind turbine noise on songbird behavior during nonbreeding season.

Anthropogenic noise is one of the fastest growing, globally widespread pollutants, affecting countless species worldwide. Despite accumulating evidence of the negative impacts of wind turbines on wildlife, little is known about how the noise they generate affects ecological systems. Songbirds may be susceptible to noise pollution due to their reliance on vocal communication and thus, in this field study, we examined how songbirds are affected by wind turbine noise. We broadcasted noise produced by one wind turbine in a migratory stopover site during the nonbreeding season. Throughout the study, we repeatedly monitored the acoustic environment and songbird community before, during, and after the noise treatments with passive acoustic monitoring and mist netting. We employed generalized linear mixed effects models to assess the impact of experimental noise treatment on birds behavior and likelihood ratio tests to compare models with variables of interest with null models. The daily number of birds in the presence of wind turbine noise decreased by approximately 30% compared with the before and after phases. This reduction had a significant spatial pattern; the largest decrease was closer to the speaker and on its downwind side, fitting measured sound propagation. Although we found no impact on species diversity, two out of three most common species showed clear avoidance behavior: 45% and 36% decrease in abundance for the lesser whitethroat (Sylvia curruca) and Sardinian warbler (Sylvia melanocephala momus), respectively. In the after phase, there were lingering effects on the lesser whitethroat. The age structure of the lesser whitethroat population was affected because only juvenile birds showed avoidance behavior. No difference in avoidance extent was found between migratory and nonmigratory species, but the impacts of displacement on migrants during stopover are especially troubling from a conservation perspective. Our results stress the need to address the impacts of noise pollution on wildlife when planning noise-generating infrastructures, such as wind turbines, to allow for sustainable development without threatening already declining songbird populations.

Health effects of wind turbine noise and road traffic noise on people living near wind turbines

Very few surveys have investigated the health effects of both wind farms and road traffic so that the public health effects of environmental stressors are broadly understood. This case-control study examined the influences of both wind turbine noise and road traffic noise on self-reported symptoms and diseases close to wind turbines and in a control area. Wind turbine sound levels 17–39 dB LAeq met new national regulation (40 dB). Daytime road traffic noise levels were 32.5–63.5 dB, sometimes exceeding the regulation (55 dB). Altogether 676 residents responded to a masked living environment questionnaire. Higher wind turbine sound level was only associated with more likely reporting wind turbine noise annoyance and not with reporting of other symptoms or chronic diseases. On the other hand, higher road traffic sound level was associated with increased odds for road traffic noise annoyance, migraine or headache, dizziness, impaired hearing, pressure in ears, tachycardia or heart palpitations, and heart disease. Road traffic exposure seems to deserve attention especially if daytime levels exceed 55 dB. The health effects of wind farms seem to be limited to noise annoyance in areas where all residents are exposed to sound levels under 40 dB.

A systematic review and meta-analysis of wind turbine noise effects on sleep using validated objective and subjective sleep assessments.

Little is known about the potential impacts of wind turbine noise (WTN) on sleep. Previous research is limited to cross-sectional studies reporting anecdotal impacts on sleep using inconsistent sleep metrics. This meta-analysis sought to comprehensively review studies evaluating the impact of WTN using widely accepted and validated objective and subjective sleep assessments. Search terms included: "wind farm noise", "wind turbine noise", "wind turbine sound", "wind turbine noise exposure" AND "sleep". Only original articles published in English published after the year 2000 and reporting sleep outcomes in the presence of WTN using polysomnography, actigraphy or psychometrically validated sleep questionnaires were included. Uniform outcomes of the retrieved studies were meta-analysed to examine WTN effects on objective and subjective sleep outcomes. Nine studies were eligible for review and five studies were meta-analysed. Meta-analyses (Hedges' g; 95% confidence interval [CI]) revealed no significant differences in objective sleep onset latency (0.03, 95% CI -0.34 to 0.41), total sleep time (-0.05, 95% CI -0.77 to 0.67), sleep efficiency (-0.25, 95% CI -0.71 to 0.22) or wake after sleep onset (1.25, 95% CI -2.00 to 4.50) in the presence versus absence of WTN (all p>.05). Subjective sleep estimates were not meta-analysed because measurement outcomes were not sufficiently uniform for comparisons between studies. This systematic review and meta-analysis suggests that WTN does not significantly impact key indicators of objective sleep. Cautious interpretation remains warranted given variable measurement methodologies, WTN interventions, limited sample sizes, and cross-sectional study designs, where cause-and-effect relationships are uncertain. Well-controlled experimental studies using ecologically valid WTN, objective and psychometrically validated sleep assessments are needed to provide conclusive evidence regarding WTN impacts on sleep.

A laboratory study on the effects of wind turbine noise on sleep: results of the polysomnographic WiTNES study.

Study ObjectivesAssess the physiologic and self-reported effects of wind turbine noise (WTN) on sleep.MethodsLaboratory sleep study (n = 50 participants: n = 24 living close to wind turbines and n = 26 as a reference group) using polysomnography, electrocardiography, salivary cortisol, and questionnaire endpoints. Three consecutive nights (23:00–07:00): one habituation followed by a randomized quiet Control and an intervention night with synthesized 32 dB LAEq WTN. Noise in WTN nights simulated closed and ajar windows and low and high amplitude modulation depth.ResultsThere was a longer rapid eye movement (REM) sleep latency (+16.8 min) and lower amount of REM sleep (−11.1 min, −2.2%) in WTN nights. Other measures of objective sleep did not differ significantly between nights, including key indicators of sleep disturbance (sleep efficiency: Control 86.6%, WTN 84.2%; wakefulness after sleep onset: Control 45.2 min, WTN 52.3 min; awakenings: Control n = 11.4, WTN n = 11.5) or the cortisol awakening response. Self-reported sleep was consistently rated as worse following WTN nights, and individuals living close to wind turbines had worse self-reported sleep in both the Control and WTN nights than the reference group.ConclusionsAmplitude-modulated continuous WTN may impact on self-assessed and some aspects of physiologic sleep. Future studies are needed to generalize these findings outside of the laboratory and should include more exposure nights and further examine possible habituation or sensitization.

Effects of wind turbine noise on the surrounding soundscape in the context of greater-prairie chicken courtship vocalizations

The development of wind energy facilities in grasslands has increased in recent years. We assessed sound levels near a 36-turbine wind energy facility in a contiguous grassland in Brown County, Nebraska, USA, using a grid sampling design. Greater prairie-chickens (Tympanuchus cupido pinnatus), a bird species of special conservation concern, occupy the landscape near the wind facility. We evaluated the variation in wind turbine noise in the landscape at 296 Hz, the average peak frequency of the critically important courtship (‘boom’) vocalization of male prairie-chickens. The levels of ambient sounds were affected by ordinal day (β = −0.0752, SE = 0.0073) and wind speed (β = 1.1679, SE = 0.0419). Sound levels (dB) at the wind facility were affected by distance to the nearest turbine (β = 0.6917, SE = 0.0111). Sound levels increased during the breeding season (ordinal day: β = 0.0166, SE = 0.0028), during the day (time of day: β = 0.0035, SE = 0.0015), and at higher wind speeds (β = 1.1929, SE = 0.0261). Sound levels were higher downwind from the facility (wind direction: β = 0.9914, SE = 0.1691) and at sites that were within the viewshed of turbines (topography: β = 0.3819, SE = 0.0824). At 100 m from the turbines, under average temporal, landscape, and wind conditions, wind turbine noise at 296 Hz was 25 dB above the ambient sound level. At 500 m from the turbines, wind turbine noise at 296 Hz was 16 dB above the ambient sound level. Our results demonstrate the variation of wind turbine noise in the soundscape and suggest a protocol for evaluating effects of wind turbine sound on sound-sensitive wildlife.

Wind Turbine Noise and Sleep: Pilot Studies on the Influence of Noise Characteristics.

The number of onshore wind turbines in Europe has greatly increased over recent years, a trend which can be expected to continue. However, the effects of wind turbine noise on long-term health outcomes for residents living near wind farms is largely unknown, although sleep disturbance may be a cause for particular concern. Presented here are two pilot studies with the aim of examining the acoustical properties of wind turbine noise that might be of special relevance regarding effects on sleep. In both pilots, six participants spent five consecutive nights in a sound environment laboratory. During three of the nights, participants were exposed to wind turbine noise with variations in sound pressure level, amplitude modulation strength and frequency, spectral content, turbine rotational frequency and beating behaviour. The impact of noise on sleep was measured using polysomnography and questionnaires. During nights with wind turbine noise there was more frequent awakening, less deep sleep, less continuous N2 sleep and increased subjective disturbance compared to control nights. The findings indicated that amplitude modulation strength, spectral frequency and the presence of strong beats might be of particular importance for adverse sleep effects. The findings will be used in the development of experimental exposures for use in future, larger studies.

Creating sound immission mimicking real-life characteristics from a single wind turbine

This paper describes a method to synthesise wind turbine sounds to be used in sleep studies using a parameter-based synthesis. The parameter values were determined using recordings of several types of operating wind turbines, thorough investigations of the recorded sounds, previous reports on wind turbine sound characteristics, and acoustic knowledge on how sound properties change from source to an outdoor receiver. The different wind turbine types are shown in the paper to have characteristic amplitude modulation (AM) spectra, with different AM strengths in different 1/3 octave bands. The statistical levels of the AM are evaluated and the correlation between A-weighted AM and AM in individual 1/3 octave bands is evaluated using linear regression. Method tests of the proposed synthesis technique show that it performs well and that wind turbine sound signals that include arbitrary AM spectra can be created. The work was part of the research project WiTNES (Wind Turbine Noise Effects on Sleep).

Corrigendum: Effects of Wind Turbine Noise on Self-Reported and Objective Measures of Sleep.

Corrigendum: Effects of Wind Turbine Noise on Self-Reported and Objective Measures of Sleep.

Male Greater Prairie-Chickens adjust their vocalizations in the presence of wind turbine noise

ABSTRACT The potential for wind energy facilities to affect species of grouse in the grasslands of the Great Plains of North America is a conservation concern. Communication by male Greater Prairie-Chickens (Tympanuchus cupido pinnatus) is essential for lek mating displays and includes low-frequency vocalizations that could be disrupted by wind turbine noise. We studied the effects of wind turbine noise on the boom, cackle, whine, and whoop vocalizations of male Greater Prairie-Chickens recorded at 14 leks located 703 m to 23 km away from a wind energy facility near Ainsworth, Brown County, Nebraska, USA, in 2013 and 2014. First, we assessed ambient sound levels at our study sites. Wind turbine noise contributed to the soundscape; leks <1,000 m from wind turbines had higher levels of ambient sound than expected on the basis of recordings obtained at remote locations. Our second objective was to determine whether the acoustic characteristics of the 4 vocalizations recorded near the wind energy facility dif...

A Review of the Possible Perceptual and Physiological Effects of Wind Turbine Noise.

This review considers the nature of the sound generated by wind turbines focusing on the low-frequency sound (LF) and infrasound (IS) to understand the usefulness of the sound measures where people work and sleep. A second focus concerns the evidence for mechanisms of physiological transduction of LF/IS or the evidence for somatic effects of LF/IS. While the current evidence does not conclusively demonstrate transduction, it does present a strong prima facia case. There are substantial outstanding questions relating to the measurement and propagation of LF and IS and its encoding by the central nervous system relevant to possible perceptual and physiological effects. A range of possible research areas are identified.

Current Situation around Wind Power Generation and Health Effects of Wind Turbine Noise

Current Situation around Wind Power Generation and Health Effects of Wind Turbine Noise

Understanding stress effects of wind turbine noise – The integrated approach

To better understand causes and effects of wind turbine (WT) noise, this study combined the methodology of stress psychology with noise measurement to an integrated approach. In this longitudinal study, residents of a wind farm in Lower Saxony were interviewed on two occasions (2012, 2014) and given the opportunity to use audio equipment to record annoying noise. On average, both the wind farm and road traffic were somewhat annoying. More residents complained about physical and psychological symptoms due to traffic noise (16%) than to WT noise (10%, two years later 7%). Noise annoyance was minimally correlated with distance to the closest WT and sound pressure level, but moderately correlated with fair planning. The acoustic analysis identified amplitude-modulated noise as a major cause of the complaints. The planning and construction process has proven to be central − it is recommended to make this process as positive as possible. It is promising to develop the research approach in order to study the psychological and acoustic causes of WT noise annoyance even more closely. To further analysis of amplitude modulation we recommend longitudinal measurements in several wind farms to increase the data base ─ in the sense of “Homo sapiens monitoring”.

On translating minimum siting distances into percentages of receiving properties meeting a stated dB(A) criterion

Around the world, minimum siting distances are used by regulators and developers to limit the effects of wind turbine noise on people. Acousticians know that the proper calculation is equal sound level contours, but customers, in this case the communities, developers, and regulators, all want simpler solutions. When creating limits for most industrial sources, noise levels from the source decrease monotonically with distance. For wind farms, the observing can be done from within the source and a monotonic function can no longer be assumed. This study makes use of data collected at over 1200 dwelling units as a part of the Health Canada Study. This paper provides a method to determine minimum siting distances based on predicted percentages of exceedances of dB(A) criterion at dwellings. A Riemann sum using CTL as a basis creates a model that can be applied to find acceptable minimum siting distances.

The effects of wind turbine noise on male Greater Prairie-Chicken vocal output during the breeding season

At a previous meeting of the ASA, we reported that the Greater Prairie-Chicken (Tympanuchus cupido pinnatus) is, in all probability, able to detect noise produced by wind turbine installations, a finding based on turbine noise output and auditory brainstem response threshold measurements (Walsh et al., 2015). That investigation was conducted in concert with an effort to determine if noise generated by a wind turbine farm located near Ainsworth, Nebraska affects the vocal output of male prairie chickens occupying breeding grounds (i.e., leks) where they perform elaborate physical and vocal mating displays. Whalen et al. (2014) paved the way to address this question by characterizing the acoustic properties of booms, cackles, whoops and whines, the primary call types produced by male birds, at sites remote from the turbine farm. At lek sites located relatively close (<1 km) to the wind farm installation, boom and whoop production levels were higher, boom durations were shorter, whine fundamental frequency was higher, and cackle biphonation occurred less frequently than among birds occupying leks located at remote locations. Although differences in vocal characteristics were statistically significant, vocal adjustments were relatively minor and the significance of wind turbine farm noise on call acoustics will be discussed. [Funded in part by USFWS-WSFR Wildlife Restoration Project W-99-R administered by the NGPC.]

On translating minimum siting distances into percentages of receiving properties meeting a stated dB(A) criterion

Around the world, minimum siting distances are used by regulators and developers to limit the effects of wind turbine noise on people. Acousticians know that the proper calculation is equal sound level contours, but customers, in this case the communities, developers, and regulators, all want simpler solutions. This study makes use of data collected at over 1200 dwelling units as a part of the Health Canada Study. This paper provides a method to determine minimum siting distances based on predicted percentages of exceedances of dB(A) criterion at dwellings.

Effects of Wind Turbine Noise on Self-Reported and Objective Measures of Sleep.

To investigate the association between self-reported and objective measures of sleep and wind turbine noise (WTN) exposure. The Community Noise and Health Study, a cross-sectional epidemiological study, included an in-house computer-assisted interview and sleep pattern monitoring over a 7 d period. Outdoor WTN levels were calculated following international standards for conditions that typically approximate the highest long-term average levels at each dwelling. Study data were collected between May and September 2013 from adults, aged 18-79 y (606 males, 632 females) randomly selected from each household and living between 0.25 and 11.22 kilometers from operational wind turbines in two Canadian provinces. Self-reported sleep quality over the past 30 d was assessed using the Pittsburgh Sleep Quality Index. Additional questions assessed the prevalence of diagnosed sleep disorders and the magnitude of sleep disturbance over the previous year. Objective measures for sleep latency, sleep efficiency, total sleep time, rate of awakening bouts, and wake duration after sleep onset were recorded using the wrist worn Actiwatch2® from a subsample of 654 participants (289 males, 365 females) for a total of 3,772 sleep nights. Participant response rate for the interview was 78.9%. Outdoor WTN levels reached 46 dB(A) with an arithmetic mean of 35.6 and a standard deviation of 7.4. Self-reported and objectively measured sleep outcomes consistently revealed no apparent pattern or statistically significant relationship to WTN levels. However, sleep was significantly influenced by other factors, including, but not limited to, the use of sleep medication, other health conditions (including sleep disorders), caffeine consumption, and annoyance with blinking lights on wind turbines. Study results do not support an association between exposure to outdoor WTN up to 46 dB(A) and an increase in the prevalence of disturbed sleep. Conclusions are based on WTN levels averaged over 1 y and, in some cases, may be strengthened with an analysis that examines sleep quality in relation to WTN levels calculated during the precise sleep period time.

Before–after field study of effects of wind turbine noise on polysomnographic sleep parameters

Wind is considered one of the most advantageous alternatives to fossil energy because of its low operating cost and extensive availability. However, alleged health-related effects of exposure to wind turbine (WT) noise have attracted much public attention and various symptoms, such as sleep disturbance, have been reported by residents living close to wind developments. Prospective cohort study with synchronous measurement of noise and sleep physiologic signals was conducted to explore the possibility of sleep disturbance in people hosting new industrial WTs in Ontario, Canada, using a pre and post-exposure design. Objective and subjective sleep data were collected through polysomnography (PSG), the gold standard diagnostic test, and sleep diary. Sixteen participants were studied before and after WT installation during two consecutive nights in their own bedrooms. Both audible and infrasound noises were also concurrently measured inside the bedroom of each participant. Different noise exposure parameters were calculated (LAeq, LZeq) and analyzed in relation to whole-night sleep parameters. Results obtained from PSG show that sleep parameters were not significantly changed after exposure. However, reported sleep qualities were significantly (P=0.008) worsened after exposure. Average noise levels during the exposure period were low to moderate and the mean of inside noise levels did not significantly change after exposure. The result of this study based on advanced sleep recording methodology together with extensive noise measurements in an ecologically valid setting cautiously suggests that there are no major changes in the sleep of participants who host new industrial WTs in their community. Further studies with a larger sample size and including comprehensive single-event analyses are warranted.

Health effects related to wind turbine noise exposure: a systematic review.

BackgroundWind turbine noise exposure and suspected health-related effects thereof have attracted substantial attention. Various symptoms such as sleep-related problems, headache, tinnitus and vertigo have been described by subjects suspected of having been exposed to wind turbine noise.ObjectiveThis review was conducted systematically with the purpose of identifying any reported associations between wind turbine noise exposure and suspected health-related effects.Data SourcesA search of the scientific literature concerning the health-related effects of wind turbine noise was conducted on PubMed, Web of Science, Google Scholar and various other Internet sources.Study Eligibility CriteriaAll studies investigating suspected health-related outcomes associated with wind turbine noise exposure were included.ResultsWind turbines emit noise, including low-frequency noise, which decreases incrementally with increases in distance from the wind turbines. Likewise, evidence of a dose-response relationship between wind turbine noise linked to noise annoyance, sleep disturbance and possibly even psychological distress was present in the literature. Currently, there is no further existing statistically-significant evidence indicating any association between wind turbine noise exposure and tinnitus, hearing loss, vertigo or headache.LimitationsSelection bias and information bias of differing magnitudes were found to be present in all current studies investigating wind turbine noise exposure and adverse health effects. Only articles published in English, German or Scandinavian languages were reviewed.ConclusionsExposure to wind turbines does seem to increase the risk of annoyance and self-reported sleep disturbance in a dose-response relationship. There appears, though, to be a tolerable level of around LAeq of 35 dB. Of the many other claimed health effects of wind turbine noise exposure reported in the literature, however, no conclusive evidence could be found. Future studies should focus on investigations aimed at objectively demonstrating whether or not measureable health-related outcomes can be proven to fluctuate depending on exposure to wind turbines.

Amplitude modulation of audible sounds by non-audible sounds: Understanding the effects of wind turbine noise

Our research has suggested a number of mechanisms by which low-frequency noise could bother individuals living near wind turbines: causing endolymphatic hydrops, exciting subconscious pathways, and amplitude modulation of audible sounds. Here we focus on the latter mechanism, amplitude modulation. We measured single-auditory-nerve fiber responses to probe tones at their characteristic frequency in cats. A 50 Hz tone, which did not cause an increase in spontaneous firing rate (i.e., was not audible to the fiber when presented alone) was used to amplitude modulate responses to the probe tone. We found that as probe frequency decreased, a lower level of the low-frequency non-audible tone was needed to achieve criterion amplitude modulation. In other words, low-frequencies that are coded in the cochlear apex require less low-frequency sound pressure level to be amplitude modulated as compared to higher-frequencies that are coded in the cochlear base. This finding was validated, and extended to lower frequencies, by amplitude modulating gross measures of onset-synchronous (compound action potentials) and phase-synchronous (auditory nerve overlapped waveforms) in guinea pigs. Our results suggest that that infrasound generated by wind turbines may cause amplitude modulation of audible sounds, which is often the basis for complaints from those living near wind turbines.