Resource Documents: Noise (659 items)
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Author: Morinaga, Makoto; et al.
Although experimental results on oppressive and vibratory feelings due to low-frequency sound are widely known, those studies were conducted about 40 years ago in Japan and some questions remain to be examined. For example, “oppressive feeling” and “vibratory feeling” are generally unfamiliar terms, but it is not clear how these terms were explained to or understood by participants. In the present study, an experiment was conducted using a method similar to the previously reported method, and the frequency characteristics of sound that induced oppressive and vibratory feelings were reviewed. Using one-third octave band noise with center frequencies ranging from 10 Hz to 630 Hz, a laboratory experiment was conducted to investigate the sound pressure level at which oppressive or vibratory feeling tended to appear for each frequency. Participants were divided into two groups. One was provided an explanation of the meaning of oppressive and vibratory feelings, and the other was provided no such explanation, and results were compared between the groups. The results suggest that sound pressure levels where these feelings tended to occur were slightly different between the two groups. Furthermore, the feelings appeared even in the higher frequency bands compared with previous studies.
Makoto MORINAGA, Ippei YAMAMOTO, Tomohiro KOBAYASHI, Defense Facilities Environment Improvement Association, Japan
Koichi MAKINO, Hiroaki OCHIAI, Kobayasi Institute of Physical Research, Japan
Hideki TACHIBANA, University of Tokyo, Japan
Proceedings of the 23rd International Congress on Acoustics, 9–13 September 2019, Aachen, Germany: pages 1478–1483
Download original document: “Frequency characteristics of oppressive and vibratory feeling to low-frequency sound”
Author: Cooper, Steven
There are technical difficulties in producing an accurate wind turbine noise signal for subjective testing of the noise characteristics for different operational scenarios of wind turbines. There are differences in the subjective response when limiting the test signals to infrasound only versus the use of full spectra. The concept of “nocebo” effect that has been presented has relied upon the use of “synthesised wind turbine infrasound” that does not reflect the signature or pressure pulsations observed in full-spectrum field measurements. The validity of “synthesised wind farm infrasound signals” that have been used in such testing is examined and compared with full-spectrum signals.
Steven Cooper, The Acoustic Group, Australia
Proceedings of the 23rd International Congress on Acoustics, 9–13 September 2019, Aachen, Germany: pages 912–919
Download original document: “The use of synthesised or actual wind turbine noise for subjective evaluation purposes”
Simplified method for determination of “amplitude modulation” of audible and inaudible wind turbine noise
Author: Cooper, Steven
The operation of a wind turbine results in a series of pulses where there is a significant instantaneous increase in the amplitude of the pressure signal dependent upon the loading (power output and wind strength) of the wind turbine. Such amplitude variations can be significant. The modulation of the amplitude of the acoustic signature for wind turbines is often referred to as “amplitude modulation”. One method of assessment of the degree of amplitude modulation for a wind turbine used in the UK is complex, time-consuming and expensive to undertake. A simplified method has been developed that is not just restricted to the dBA level and can be used to cover both inaudible and audible dynamically pulsed amplitude modulation. This simplified analysis method is not just restricted to wind turbine noise but has uses for other pulsating noise sources. Investigation of recreational music and industrial noise sources that give rise to the generation of pulsations occurring at an infrasound rate using the simple methodology is discussed.
Steven Cooper, The Acoustic Group, Australia
Proceedings of the 23rd International Congress on Acoustics, 9–13 September 2019, Aachen, Germany: pages 920–927
Download original document: “A simplified method for determination of “amplitude modulation” of audible and inaudible wind turbine noise”
Wind turbine audibility and noise annoyance in a national U.S. survey: Individual perception and influencing factors
Author: Haac, T. Ryan; et al.
With results from a nationwide survey sponsored by the U.S. Department of Energy, factors that affect outdoor audibility and noise annoyance of wind turbines were evaluated. Wind turbine and summer daytime median background sound levels were estimated for 1043 respondents. Wind turbine sound level was the most robust predictor of audibility yet only a weak, albeit significant, predictor of noise annoyance. For each 1 dB increase in wind turbine sound level (L1h-max), the odds of hearing a wind turbine on one’s property increased by 31% [odds ratio (OR): 1.31; 95% CI (confidence interval): 1.25-1.38] and the odds of moving to the next level of annoyance increased by 9% (OR: 1.09; 95% CI: 1.02-1.16). While audibility was overwhelmingly dependent on turbine sound level, noise annoyance was best explained by visual disapproval (OR: 11.0; 95% CI: 4.8-25.4). The final models correctly predict audibility and annoyance level for 80% and 62% of individuals, respectively. The results demonstrate that among community members not receiving personal benefits from wind projects, the Community Tolerance Level of wind turbine noise for the U.S. aligns with the international average, further supporting observations that communities are less tolerant of wind turbine noise than other common environmental noise sources at equivalent A-weighted sound levels.
T. Ryan Haac, Kenneth Kaliski, and Matthew Landis, RSG, White River Junction, Vermont
Ben Hoen and Joseph Rand, Lawrence Berkeley National Laboratory, Berkeley, California
Jeremy Firestone, College of Earth, Ocean, and Environment, University of Delaware, Newark
Debi Elliott, Survey Research Lab, Portland State University, Oregon
Gundula Hübner and Johannes Pohl, Institute of Psychology, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany
Journal of the Acoustical Society of America, August 2019. 146(2):1124. doi: 10.1121/1.5121309.
Download original document: “Wind turbine audibility and noise annoyance in a national U.S. survey: Individual perception and influencing factors”