Wind Turbine Noise Annoyance Research Articles

Wind farm noise prediction and auralization

This work presents the application and validation of a novel auralization approach for the evaluation of wind turbine noise annoyance under diverse conditions. The approach is based on the decomposition of each turbine blade into elementary short-segment sources, whose acoustic radiation in the far field is obtained by coupling Amiet’s emission model with the Harmonoise engineering model for outdoor sound propagation. The transfer functions between the elementary source positions and receivers are obtained. Then, the average and instantaneous sound pressure levels are calculated over one blade rotation. The realism of the audio signals is evaluated through listening tests with audio signals of the real and simulated environments. The predicted noise spectra from five wind turbines capture well the measured trends and the absolute levels. Finally, we present a study of the weather effects on noise emissions and propagation by using the numerical model developed.

Experimental studies of the impact of amplitude modulation (AM) and tonality on the annoyance of wind turbine noise in the low frequency (LF) range

Amplitude modulation (AM) testing is most often limited to the band from 100 Hz to 800 Hz. The impact of AM and tonality on the annoyance of wind turbine (WT) noise in the frequency range below 100 Hz was undertaken as part of the work. In many works, complaints about the annoyance of WT noise in the low frequency (LF) band are raised, although the energy levels in this band do not exceed the threshold of perception. One of the reasons for such complaints may be AM and tonality. Acoustic signals were recorded in the band from 1 Hz to 20 kHz, at distances from 250 to 1500 m from the turbine at various wind speeds. From the recorded results, samples with the presence of AM and samples with tonal components were selected. The modulation depth, tonality or frequency modulation (FM) were determined for each sample. Preliminary listening tests were also carried out, in which the stimulus was the samples of recordings with AM and tonal components. The listening range was limited to the LF band. Preliminary studies showed no significant differences in noise perception between these samples. Further research is planned with recordings of greater tonality and AM depth.

Subjective evaluation of wind turbine noise using 3-dimensional audio- visual reproduction system

In recent years, the installation of new wind turbines has been promoted in Japan. Since wind turbines are often installed in quiet countryside, it is necessary to properly evaluate the noise impact of wind turbine installation. Since wind turbines are thought to have visual as well as auditory effects, we conducted a subjective evaluation experiment on the loudness and annoyance of wind turbine noise (WTN) and road traffic noise (RTN) by magnitude estimation method, using a three-dimensional audio-visual reproduction system consisting of 6 channels of loudspeakers installed around the sound receiving point and a dome screen. As a result, the loudness and annoyance of WTN tended to be evaluated higher than that of RTN. These results were considered to be influenced by the amplitude modulation called "swish sound" and the low-frequency dominant frequency characteristics, which are characteristics of WTN. In addition, when comparing the differences in loudness and annoyance with and without visual information, the two attributes tended to be lower when visual information was present.

Assessment of wind turbine noise in laboratory conditions

The development of wind energy is accompanied by an increase in the number of people whose workplaces and/or places of residence are located near wind farms as well as is accompanied by numerous questions about the influence of wind farms on human. Among the factors related to the operation of wind farms, wind turbine noise has to be seen as a source of annoyance for both people living and working near wind farms. A test bench to conduct noise annoyance tests of different types of wind turbine noise in laboratory conditions have been developed at the Central Institute for Labour Protection - National Research Institute. The test bench is based on a multi-channel sound reproducing system using the DANTE network and is compiled in the acoustic test chamber. The test bench consists of 18 speakers (including studio monitors and woofers) and a laboratory source of infrasound. During exposure to 6 different virtual acoustic environments, representing different wind turbine noise, 40 participants assessed wind turbine noise annoyance. The paper describes the test bench and the results of the studies concerning the assessment of wind turbine noise annoyance.

Interlaboratory comparison of ISO 23351-1: speech level reduction of furniture ensembles

We examined the effects of both wind turbine noise and road traffic noise on symptoms and diseases close to wind turbines and in a control area. Wind turbine sound levels were between 1739 dB LAeq and met the Finnish regulation (40 dB). Daytime road traffic noise levels were 32.5-63.5 dB. Altogether 676 residents responded to the questionnaire. Higher wind turbine sound level was associated with more likely reporting wind turbine noise annoyance and not with reporting of symptoms or chronic diseases. Higher road traffic sound level was associated with higher probability of road traffic noise annoyance, migraine or headache, dizziness, impaired hearing, pressure in ears, tachycardia or heart palpitations, and heart disease. 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. The study has strong practical relevance since new wind power areas always fulfill this 40 dB regulation in Finland. On the other hand, more than 600.000 inhabitants are exposed to road traffic noise levels above 55 dB in Finland. Because high road traffic noise is associated with elevated prevalence of symptoms and a disease in our study, and several previous international studies have found even more serious health effects of road traffic noise, this issue deserves higher concern in the future.

Understanding subjective and situational factors of wind turbine noise annoyance

One of the most relevant acceptance factors of local wind turbines (WTs) are noise emissions. To better understand why some residents experience stress effects from wind turbines a field study with strongly annoyed residents (SAR) was conducted. A convenience sample of residents (N = 148) in the proximity of a wind farm in Germany were interviewed using a standardised questionnaire. Objective features, such as number of visible WTs and distance to the nearest WT, could not explain the experienced noise annoyance substantially. Instead, SAR were characterised by a negative perception of both procedural as well as distributive fairness, the assumed decrease of property value due to the WTs, a negative attitude towards the local wind farm (but not to WTs in general), and higher noise sensitivity. Additionally, SAR reported to be affected daily during the night in their bedrooms, while other residents experience annoying situations more likely when they are directly exposed to WTs. Fast wind speeds, wet weather and, occasionally, frost or fog were associated with annoying situations. In accord with recent research, we recommend to increase consideration of participation and fairness in the initial planning of a wind farm to increase acceptance and reduce annoyance. Additionally, to reduce the fear of negative health impacts and to increase acceptance, mitigation measures depending on specific weather conditions seem to be promising.

Local residents’ attitudes about wind farms and associated noise annoyance in South Korea

Although the deployment of wind energy has gradually increased in South Korea, local opposition to the development of wind projects has frequently been reported; this could retard the deployment of wind power in South Korea. Noise from the operation of wind turbines is claimed to be the major reason for opposition. This study explored factors related to local residents’ attitudes toward adjacent wind farms and the noise annoyance associated with them. Multivariate linear regression models were adopted to analyze a survey conducted in three counties in South Korea. In the analysis of attitudes, the perceived fairness of the development process was the most influential independent variable, followed by visual evaluation of wind farms and thoughts on whether more wind energy should be installed within the country. In the analysis of noise annoyance, current attitude toward existing wind farms was the most influential factor, followed by factors related to the visibility of wind farms and visual evaluation of them. These findings suggest that planning processes that engage local residents from the start of project development and empower them to influence wind farm layout designs are effective in securing community acceptance and even in alleviating the perceived annoyance of wind turbine noise.

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.

Amplitude modulations increase annoyance due to wind turbine noise immission

Current literature suggests that annoyance of wind turbine noise is strongly affected by amplitude modulations (AM). A survey was carried out at five German residential study sites near wind turbines with a total of about 500 residents to study the effects of AM in more detail. Annoyance, disturbances, and the perception of wind turbine noise characteristics, including AM, were assessed. For each participant, address-related exposure to rating levels of wind turbines was estimated. Further, we carried out headphone-based listening experiments with participants from three of the five study areas and with non-exposed participants from another 'control' location. In the listening experiments, perceived annoyance was rated for varying AM and for different A-weighted sound pressure levels for a total number of 79 subjects. As expected, the results show an increase in annoyance with sound pressure level. Furthermore, annoyance increased significantly with the extent of amplitude modulations. Interestingly, annoyance showed a strong rise as soon as amplitude modulations became audible in the signal and this rise was hardly affected by the sound pressure level. In our contribution, we present comparisons of the results of the survey and the listening experiments.

1.5 MW 풍력 터빈 소음 측정 및 저주파 소음 특성 분석

The noise from a 1.5 MW wind turbine was measured and the apparent sound power level, tonal audibility, and spectrum balance were analyzed. The apparent sound power level and tonal audibility were analyzed according to IEC 61400-11: ed3. (2012-11). The measured noise data at the turbine site was mainly in the north-west (NW) and north-north-west (NNW) directions, and approximately 500 and 250 samples of total noise and background noise data were obtained. Three tone components were observed in the low frequency region below 100 Hz. The tones in the low frequency critical band with a center frequency of 78.1 Hz were found to have a higher level than the hearing threshold. The possibility of wind turbine noise annoyance was also analyzed through the spectrum balance analysis.

Variables associated with wind turbine noise annoyance and sleep disturbance

Wind turbine noise (WTN) increases the risk of WTN annoyance and self-reported sleep disturbance, which in turn can influence people's well-being. However, the sound level explains only a small fraction of WTN annoyance. The purpose of our study was to determine how acoustic and various non-acoustic variables are associated with WTN annoyance indoors, WTN annoyance outdoors, and sleep disturbance due to WTN. 318 permanent residents living within 2 km of the nearest wind turbine in three different areas of Finland responded to the questionnaire. The turbines were relatively large, within 3 and 5 megawatts. The explanatory models were developed using binary logistic regression. The models predicting WTN annoyance had the predictive strengths of 67% for indoor and 71% for outdoor WTN annoyance. The concern for health effects was the most important factor related to both WTN annoyance and sleep disturbance due to WTN. Other factors explaining WTN annoyance were area, noise sensitivity, and general attitude towards wind power as a form of energy production. Sound level explained also outdoor annoyance and sleep disturbance related to WTN. Furthermore, women were more annoyed indoors and reported more sleep disturbance due to WTN than men. We believe that the health concerns and WTN annoyance could be reduced by providing the residents with more fact-based information about wind power and more interactive and transparent communication concerning the planning and building processes.

Estimating community tolerance for wind turbine noise annoyance

A-weighted WTN contributed less than 10% to the strength of the multiple regression model developed for wind turbine noise (WTN) annoyance in Health Canada’s Community Noise and Health Study (CNHS). Improvements required consideration of non-LAeq variables unknown or even inapplicable beyond the CNHS. To facilitate cross-study comparisons, an analysis of WTN annoyance was conducted based on the community tolerance level (CTL) model. The rate of increase in WTN annoyance was effectively estimated using a loudness function, as shown in Eq. (1). %HA = 100 exp (-(1/[10((DNL-CTL + 5.306)/10)]0.3)). (1) By convention, CTL is the DNL from Eq. (1) where 50% of the community would be highly annoyed. The CTL for WTN annoyance from field studies published to date ranges from 57.1 to 64.6 DNL (mean = 62, σ = 3). CTL values developed by others for transportation noise sources suggest that, on average, communities are between 11 dB and 26 dB less tolerant of WTN than of other sources, depending on the source. Confidence in these results should increase as future studies in this area produce additional estimates for the relationship between WTN level and the prevalence of high annoyance. The CTL analytical methods, assumptions, strengths, and limitations are presented.

Indoor simulation of amplitude modulated wind turbine noise

AbstractWind energy is the world's fastest‐growing renewable energy source; as a result, the number of people exposed to wind farm noise is increasing. Because of its broadband amplitude‐modulated characteristic, wind turbine noise (WTN) is more annoying than noise produced by other common community/industrial sources. As higher frequencies are attenuated by air absorption and building transmission, the noise from modern large wind farms is mainly below 1000 and 500 Hz for outdoor and indoor conditions, respectively. Many WTN complaints relate to indoor, nighttime conditions when background noise levels are lower. As recently reported, indoor noise has the potential to cause sleeping disorders. Studies on human response to amplitude modulated WTN have been mainly focused on the outdoors, where a large amount of measured data exists. This is not the case for indoors, where it is much harder to gather data. Hence, there is a need to understand the transmission of WTN into dwellings and to develop indoor annoyance metrics. In this article, we investigate the transmission of WTN into residential‐type structures. Using an outdoor WTN recording and structures with different properties/configurations, we made a series of computer simulations for indoor noise predictions and assessed the results employing several widely used metrics for WTN, for example, spectral content, modulation depth and overall levels. In general, the indoor noise levels are higher, and the average modulation depth is similar to those of outdoor recordings. In addition, there is a significant change in the spectral shape. These results could potentially explain indoor WTN annoyance. Copyright © 2016 John Wiley & Sons, Ltd.

Evaluating a visual-acoustic simulation for wind park assessment

The implementation of wind parks often fails due to lack of public acceptance. Visual-acoustic landscape simulations of wind parks offer a potential instrument for public participation, allowing experiencing the visual and the acoustic landscape impact. However, before such simulations can be implemented in practice, they need to be validated.In this article, we develop and apply an approach to evaluate visual-acoustic simulations for assessing wind park perceptions. The approach compares whether simulations generate similar reactions of respondents as recordings of the same environments. The survey participants made a visual and an acoustic assessment of the landscape represented by recordings and by simulations.The results show that there was nearly no difference in the rating of the annoyance of wind turbine noise between the recordings and the simulation. With regard to the visual landscape assessment the ratings based on the simulations were lower than the ones based on the recordings. The approach indicates aspects of the simulation that differ compared to the recording, such as coherent coloring and animation of landscape elements. The rating differences between the recordings and the simulations of both, the visual and the acoustic perception have to be considered when using the simulations for further studies.Overall, the described approach was successfully applied and contributes to validity testing methods. However, this is a preliminary and exploratory study. A complete test of validity should compare the simulations to the actual environment, which should be further studied.

Personal and situational variables associated with wind turbine noise annoyance.

The possibility that wind turbine noise (WTN) affects human health remains controversial. The current analysis presents results related to WTN annoyance reported by randomly selected participants (606 males, 632 females), aged 18-79, living between 0.25 and 11.22 km from wind turbines. WTN levels reached 46 dB, and for each 5 dB increase in WTN levels, the odds of reporting to be either very or extremely (i.e., highly) annoyed increased by 2.60 [95% confidence interval: (1.92, 3.58), p < 0.0001]. Multiple regression models had R(2)'s up to 58%, with approximately 9% attributed to WTN level. Variables associated with WTN annoyance included, but were not limited to, other wind turbine-related annoyances, personal benefit, noise sensitivity, physical safety concerns, property ownership, and province. Annoyance was related to several reported measures of health and well-being, although these associations were statistically weak (R(2 )< 9%), independent of WTN levels, and not retained in multiple regression models. The role of community tolerance level as a complement and/or an alternative to multiple regression in predicting the prevalence of WTN annoyance is also provided. The analysis suggests that communities are between 11 and 26 dB less tolerant of WTN than of other transportation noise sources.

Effect of modulation depth, frequency, and intermittence on wind turbine noise annoyance.

Amplitude modulation (AM) may be an important factor for the perceived annoyance of wind turbine noise (WTN). Two AM types, typically referred to as "normal AM" (NAM) and "other AM" (OAM), characterize WTN AM, OAM corresponding to having intermittent periods with larger AM depth in lower frequency regions than NAM. The extent to which AM depth, frequency, and type affect WTN annoyance remains uncertain. Moreover, the temporal variations of WTN AM have often not been considered. Here, realistic stimuli accounting for such temporal variations were synthesized such that AM depth, frequency, and type, while determined from real on-site recordings, could be varied systematically. Listening tests with both original and synthesized stimuli showed that a reduction in mean AM depth across the spectrum led to a significant decrease in annoyance. When the spectrotemporal characteristics of the original far-field stimuli and the temporal AM variations were taken into account, the effect of AM frequency remained limited and the presence of intermittent OAM periods did not affect annoyance. These findings suggest that, at a given overall level, the AM depth of NAM periods is the most crucial AM parameter for WTN annoyance.

Health and well-being related to wind turbine noise exposure: Summary of results

This paper summarizes the results of the Health Canada Wind Turbine Noise and Health Study. One participant between the ages of 18–79 years was randomly selected from each household. The final sample included 1238 participates (606 males) living between 0.25 and 11.22 km from wind turbines. The response rate was 78.9% and did not significantly vary across sampling strata or between provinces. Wind turbine noise (WTN) exposure was not found to be related to hair cortisol concentrations, resting blood pressure, resting heart rate, or any of the measured sleep parameters. Self-reported results obtained through an in-person questionnaire do not provide support for an association between increasing WTN levels and self-reported sleep disturbance, use of sleep medication, or diagnosed sleep disorders. Similarly, no significant association was found between WTN levels and self-reported migraines, tinnitus, dizziness, diabetes, asthma, hypertension, perceived stress, or any measure of quality of life. Statistically significant exposure-response relationships were observed between increasing WTN levels and an increase in the prevalence of long term high annoyance towards several wind turbine features, including: noise, shadow-flicker, visual impacts, and vibrations. The influence of background noise on annoyance and the association between WTN annoyance and other reported and measured outcomes is presented.

Annoyance of wind-turbine noise as a function of amplitude-modulation parameters

Amplitude modulation (AM) has been suggested as an important factor for the perceived annoyance of wind-turbine noise (WTN). Two AM types, typically referred to as “normal AM” and “other AM,” depending on the AM extent and frequency region, have been proposed to characterize WTN AM. The extent to which AM depth, frequency, and type affect WTN annoyance is a matter of debate. In most subjective studies, the temporal variations of WTN AM have not been considered. Here, a sinusoidally modulated WTN model accounting for temporal AM variations was used to generate realistic artificial stimuli in which the AM depth, frequency, and type, while determined from real on-site recordings, could be varied systematically. Subjective listening tests with such stimuli showed that a reduction in AM depth, quantified by the modulation depth spectrum, led to a significant decrease in annoyance. When the spectrotemporal characteristics of the original far-field stimuli were included in the model and the temporal AM variations were taken into account by varying the modulation index over time, neither AM frequency nor AM type were found to significantly affect annoyance. These findings suggest that the effect of AM parameters on WTN annoyance may depend on the intermittent nature of WTN AM.

Listening Test Comparing A-Weighted and C-Weighted Sound Pressure Level as Indicator of Wind Turbine Noise Annoyance

A listening test was conducted to investigate whether A-or C-weighed sound levels are most suitable as indicator of annoyance due to wind turbine noise. The tests consisted of fifteen different win ...

Annoyance, detection and recognition of wind turbine noise

Annoyance, recognition and detection of noise from a single wind turbine were studied by means of a two-stage listening experiment with 50 participants with normal hearing abilities. In-situ recordings made at close distance from a 1.8-MW wind turbine operating at 22rpm were mixed with road traffic noise, and processed to simulate indoor sound pressure levels at LAeq 40dBA. In a first part, where people were unaware of the true purpose of the experiment, samples were played during a quiet leisure activity. Under these conditions, pure wind turbine noise gave very similar annoyance ratings as unmixed highway noise at the same equivalent level, while annoyance by local road traffic noise was significantly higher. In a second experiment, listeners were asked to identify the sample containing wind turbine noise in a paired comparison test. The detection limit of wind turbine noise in presence of highway noise was estimated to be as low as a signal-to-noise ratio of -23dBA. When mixed with local road traffic, such a detection limit could not be determined. These findings support that noticing the sound could be an important aspect of wind turbine noise annoyance at the low equivalent levels typically observed indoors in practice. Participants that easily recognized wind-turbine(-like) sounds could detect wind turbine noise better when submersed in road traffic noise. Recognition of wind turbine sounds is also linked to higher annoyance. Awareness of the source is therefore a relevant aspect of wind turbine noise perception which is consistent with previous research.