Sound level distributions on a circular ground board for wind turbine noise measurements

Noise from wind turbines is one of the most important factors affecting the health, welfare, and human sleep. This research was carried out to study the effect of wind turbine noise on workers' sleep disorder. For this, Manjil Wind Farm, because of the greater number of staff and turbines than other wind farms in Iran, was chosen as case study. A total number of 53 participants took part in this survey. They were classified into three groups of mechanics, security, and official. In this study, daytime sleepiness data of workers were gathered using Epworth Sleepiness Scales (ESS) was used to determine the level of daytime sleepiness among the workers. The 8-h equivalent sound level (LAeq,8h) was measured to determine the individuals' exposure at each occupational group. Finally, the effect of sound, age, and workers' experience on individuals' sleep disorder was analyzed through multiple regression analysis in the R software. The results showed that there was a positive and significant relationship between age, workers' experience, equivalent sound level, and the level of sleep disorder. When age is constant, sleep disorder will increase by 26% as per each 1 dB increase in equivalent sound level. In situations where equivalent sound level is constant, an increase of 17% in sleep disorder is occurred as per each year of work experience. Because of the difference in sound exposure in different occupational groups. The effect of noise in repairing group was about 6.5 times of official group and also 3.4 times of the security group. Sleep disorder effect caused by wind turbine noise in the security group is almost two times more than the official group. Unlike most studies on wind turbine noise that address the sleep disorder among inhabitants nearby wind farms, this study, for the first time in the world, examines the impact of wind turbine noise on sleep disorder of workers who are more closer to wind turbines and exposed to higher levels of noise. So despite all the good benefits of wind turbines, it can be stated that this technology has health risks for all those exposed to its sound. However, further research is needed to confirm the results of this study.

Download Full-text

Wind turbine noise measurements in controlled conditions

International Journal of Aeroacoustics ◽

10.1177/1475472x17729976 ◽

2017 ◽

Vol 16 (7-8) ◽

pp. 649-665

Author(s):

Koen Boorsma ◽

Gerard Schepers

Keyword(s):

Wind Turbine ◽

Wind Turbine Noise ◽

Controlled Conditions ◽

Noise Measurements

Download Full-text

Noise Annoyance Caused by Amplitude Modulated Sounds Resembling the Main Characteristics of Temporal Wind Turbine Noise

Archives of Acoustics ◽

10.1515/aoa-2016-0022 ◽

2016 ◽

Vol 41 (2) ◽

pp. 221-232 ◽

Cited By ~ 7

Author(s):

Honorata Hafke-Dys ◽

Anna Preis ◽

Tomasz Kaczmarek ◽

Adam Biniakowski ◽

Paweł Kleka

Keyword(s):

Wind Turbine ◽

Modulation Depth ◽

Sound Level ◽

Broadband Noise ◽

Wind Turbine Noise ◽

Noise Annoyance ◽

Significant Difference ◽

Different Types ◽

Modulation Rate ◽

Listening Experiment

Abstract Annoyance ratings for artificially created noises, resembling the main characteristics of temporal wind turbine noise, were studied by means of a listening experiment involving 21 participants with normal hearing. Three types of stimuli were examined: broadband noise (−4 dB/octave), noise generated by moving cars, and narrowband noise. All stimuli had the sound level fluctuations typical for wind turbine noise. The magnitude of the sound level fluctuations was measured in a quantitative way, by using the characteristics of amplitude modulated sound: modulation rate and modulation depth. Our aim was to examine how the modulation rate and the modulation depth influence the noise annoyance assessment of broadband and narrowband amplitude modulated noises. Three different modulation rates, 1, 2 and 4 Hz, and sound level fluctuations (a measure of the modulation depth), 3, 6, 9 dB, were applied to each type of stimuli (with exception of noise generated by the moving cars) and investigated. The participants in the listening experiment were presented with sound stimuli in laboratory conditions and asked to rate their annoyance on a numerical scale. The results have shown a significant difference between the investigated conditions. The effect was particularly strong between the annoyance judgments of different types of noise (narrow and broadband), and modulated versus unmodulated noises. Temporal fluctuations occurring in wind turbine noise are very pertinent to the perception of annoyance and could be responsible for its being a relatively annoying noise source. The obtained results were discussed and compared to the typical modulation rates and level changes that occur in recordings of real wind turbine noise.

Download Full-text

Case Study in a Working Environment Highlighting the Divergence between Sound Level and Workers’ Perception towards Noise

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17176122 ◽

2020 ◽

Vol 17 (17) ◽

pp. 6122

Author(s):

Chun-Yip Hon ◽

Illia Tchernikov ◽

Craig Fairclough ◽

Alberto Behar

Keyword(s):

Noise Exposure ◽

Health And Safety ◽

Sound Level ◽

Working Environment ◽

Noise Levels ◽

Hearing Conservation ◽

Attitudes And Perceptions ◽

Noise Measurements ◽

Survey Responses ◽

Excessive Noise

Excessive noise levels are a prevalent issue in food processing operations and, although there have been numerous studies on occupational noise, no single study has used a concurrent mixed-methods approach. Employing this study design allows for an understanding of the level of convergence (similarity) between measured noise levels and workers’ attitudes and perceptions towards noise. This, in turn, allows for the identification of potential challenges with respect to the implementation of hearing conservation efforts. In this study, spot noise measurements were collected using a sound level meter. One-on-one interviews were conducted with workers to determine attitudes and perceptions towards noise in their workplaces. Subsequently, the results of the noise measurements (quantitative data) were integrated with the survey responses (qualitative data) to identify convergence. The majority of the noise measurements were found to exceed 85 dBA—the criterion mandated by the local occupational health and safety legislation. Although all study participants felt that it was noisy in the workplace, a large proportion of respondents indicated that the noise was not bothersome. With workers’ perception being contradictory to the measured noise levels, it is a challenge to implement hearing conservation measures unless changes are made to raise the awareness of the risks associated with excessive noise exposure.

Download Full-text