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

2014 ◽  
Vol 100 (5) ◽  
pp. 842-847 ◽  
Author(s):  
Karl Bolin ◽  
Gösta Bluhm ◽  
Mats E. Nilsson
Keyword(s):  
Wind Turbine ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Listening Test ◽  
Wind Turbine Noise ◽  
Noise Annoyance

Amplitude modulations increase annoyance due to wind turbine noise immission

2021 ◽  
Vol 263 (2) ◽  
pp. 4048-4057
Author(s):  
Christoph Pörschmann ◽  
Stephan Großarth ◽  
Johannes M. Arend ◽  
Sebastian Schmitter ◽  
Dirk Schreckenberg ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Current Literature ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Wind Turbine Noise ◽  
Control Location ◽  
Noise Characteristics ◽  
Study Sites

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.

scholarly journals Comparing sound emergence and sound pressure level as predictors of short-term annoyance from wind turbine noise

Acta Acustica ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 10
Author(s):  
Guillaume Dutilleux ◽  
Jean Fosset
Keyword(s):  
Wind Turbine ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Short Term ◽  
Limit Values ◽  
Wind Turbine Noise ◽  
Published Evidence ◽  
Sound Pressure Levels ◽  
Wind Energy Development

While most of the countries over the world rely on sound-pressure-level-based limit values to regulate wind energy development, sound emergence as defined in ISO 1996-1 is used in a few national legislations but also in international guidelines. There is however no published evidence that sound emergence is a relevant noise descriptor for that kind of source, namely that there is a correlation between this metric and perception or annoyance. A listening test was carried out to evaluate the relative merits of sound pressure level and sound emergence as predictors of annoyance from wind turbine noise. The test samples consisted of 45 30-s wind turbine sounds at three different A-weighted sound pressure levels and five different signal-to-noise ratios. Thirty two persons rated the test samples according to the ISO 15666 standard scale in a dry room equipped with loudspeakers. The results indicate that short term annoyance is better predicted by A-weighted sound pressure levels than by sound emergence. It is also observed that sound emergence is a poor predictor of the audibility of wind turbine sounds.

scholarly journals Wind turbine sound pressure level calculations at dwellings

2016 ◽  
Vol 139 (3) ◽  
pp. 1436-1442 ◽  
Author(s):  
Stephen E. Keith ◽  
Katya Feder ◽  
Sonia A. Voicescu ◽  
Victor Soukhovtsev ◽  
Allison Denning ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level

A Criterion for Predicting the Annoyance Due to Lower Level Low Frequency Noise

1983 ◽  
Vol 2 (4) ◽  
pp. 160-168 ◽  
Author(s):  
N. Broner ◽  
H.G. Leventhall
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Low Frequency ◽  
Threshold Effect ◽  
Pressure Level ◽  
The Other ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Estimation Task ◽  
Noise Annoyance

In a study of the annoyance due to low frequency noise, 75 subjects (consisting of 21 complainants and 54 controls) carried out a magnitude estimation task and rated the annoyance due to lower-level low frequency noise (55dB–75dB). After allowing for a threshold effect, it was found that the E-weighted sound pressure level was, in general, the best predictor of lower-level low frequency noise annoyance. However, it was not a significantly better predictor than any of the other nine noise measures considered. The widely available dB(A) noise measure was therefore suggested as a useful predictor of group annoyance due to lower-level low frequency noise.

scholarly journals Effect of Airfoil Concavity on Wind Turbine Blade Performances

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Jianlong Ma ◽  
Yafan Duan ◽  
Ming Zhao ◽  
Wenchun Lv ◽  
Jianwen Wang ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Aerodynamic Performance ◽  
Pressure Level ◽  
Wind Turbine Blade ◽  
Wake Flow ◽  
Suction Surface ◽  
Horizontal Axis Wind Turbine

Although the optimization of wind turbine blade aerodynamic performance has achieved fruitful results, whether airfoil concavity, an important method for preventing flow separation, is also feasible for improving the aerodynamic performance has not been confirmed scientifically. Thus, we selected the blade of a small horizontal-axis wind turbine as a research model and proposed an optimization method based on airfoil concavity near the trailing edge of the blade suction surface. The experimental results showed that airfoil concavity improved blade aerodynamic performance by 3–15%. Subsequently, its effects on the sound pressure level within the wake flow field were investigated using an acoustic array, and the results suggested that the sound pressure level was reduced by 9.6–15.8%. Lastly, a modal test of the rotor blade was conducted. Although the natural frequencies of the 1st and 2nd order vibrations had hardly changed, their vibrational stiffness were increased by 7 and 4.9%, respectively, which indicated that airfoil concavity significantly improved structural robustness.

scholarly journals A Ffowcs Williams-Hawkings numerical aeroacoustic study of varied and fixed-pitch blades of an H-Rotor vertical axis wind turbine

2021 ◽  
Vol 347 ◽  
pp. 00013
Author(s):  
Errol Molatudi ◽  
Thokozani Justin Kunene ◽  
Lagouge Kwanda Tartibu
Keyword(s):  
Wind Turbine ◽  
Vortex Shedding ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Time History ◽  
Vertical Axis ◽  
Pressure Level ◽  
Navier Stokes ◽  
Vertical Axis Wind Turbine ◽  
Airfoil Blades

The effects of sound pressure level at two observation positions of a fixed and varied blade pitch angle at Low-Mach unsteady incompressible Reynolds-Average Navier-Stokes flow approach, on an H-rotor Vertical Axis Wind Turbine. The objective of the study is to compare the noise dissipation and output power/energy of the airfoil blades design of the vertical axis wind turbine in residential zones. The Ffowcs Williams-Hawkings (FHWH) techniques were applied to validate the output noise and vortex shedding of the different angles of attacks (AoA). The study postulated that the time history of the calculated sound pressure level at two observers positions: the aeroacoustic, blade vortex interaction noise, flow separations, dynamic stall experience from varied angled of attacks are found to produces less noise and vortex shedding compared to the fixed angle of attack.

Contributions of Voice and Nonverbal Communication to Perceived Masculinity–Femininity for Cisgender and Transgender Communicators

2020 ◽  
Vol 63 (4) ◽  
pp. 931-947
Author(s):  
Teresa L. D. Hardy ◽  
Carol A. Boliek ◽  
Daniel Aalto ◽  
Justin Lewicke ◽  
Kristopher Wells ◽  
...  
Keyword(s):  
Fundamental Frequency ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Vocal Tract ◽  
Presentation Mode ◽  
Pressure Level ◽  
Presentation Modes ◽  
Audiovisual Stimuli ◽  
Vocal Tract Resonance ◽  
Point Light

Purpose The purpose of this study was twofold: (a) to identify a set of communication-based predictors (including both acoustic and gestural variables) of masculinity–femininity ratings and (b) to explore differences in ratings between audio and audiovisual presentation modes for transgender and cisgender communicators. Method The voices and gestures of a group of cisgender men and women ( n = 10 of each) and transgender women ( n = 20) communicators were recorded while they recounted the story of a cartoon using acoustic and motion capture recording systems. A total of 17 acoustic and gestural variables were measured from these recordings. A group of observers ( n = 20) rated each communicator's masculinity–femininity based on 30- to 45-s samples of the cartoon description presented in three modes: audio, visual, and audio visual. Visual and audiovisual stimuli contained point light displays standardized for size. Ratings were made using a direct magnitude estimation scale without modulus. Communication-based predictors of masculinity–femininity ratings were identified using multiple regression, and analysis of variance was used to determine the effect of presentation mode on perceptual ratings. Results Fundamental frequency, average vowel formant, and sound pressure level were identified as significant predictors of masculinity–femininity ratings for these communicators. Communicators were rated significantly more feminine in the audio than the audiovisual mode and unreliably in the visual-only mode. Conclusions Both study purposes were met. Results support continued emphasis on fundamental frequency and vocal tract resonance in voice and communication modification training with transgender individuals and provide evidence for the potential benefit of modifying sound pressure level, especially when a masculine presentation is desired.

Sign in / Sign up

Export Citation Format

Share Document