Experimental study to determine wind-induced noise and windscreen attenuation effects on microphone response for environmental wind turbine and other applications

Hessler, George F.; Hessler, David M.; Brandstätt, Peter; Bay, Karlheinz

doi:10.3397/1.2949926

Cited by 9 publications

(3 citation statements)

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“…There have been studies with respect to measuring wind turbine infrasound and low frequency noise, in relation to the attenuation of wind directly on the microphone; various size windscreens are identified in the US ANSI/ASA Standard S12.9-2016/Part 7 [60]. Hansen and others have undertaken investigations of double layered wind screens [61][62][63][64][65], for low frequency and infrasound wind turbine measurements.…”

Section: Fundamental Issues With Acoustic Compliance Testingmentioning

confidence: 99%

Determination of Acoustic Compliance of Wind Farms

Cooper

Chan

2020

Acoustics

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An issue exists around the world of wind farms that comply with permit conditions giving rise to noise complaints. Approval limits are normally expressed in A-weighted levels (dB(A)) external to residential receivers. The distance from the wind farm to residential receivers can result in difficulty in establishing the dB(A) contribution of the wind farm, as the overall noise includes background noise that can provide masking of the wind turbine noise. The determination of the ambient background at a receiver location (without the influence of the wind farm) presents challenges, as the background level varies with the wind and different seasons throughout the year. On-off testing of wind farms does not normally occur at high wind farm output and limits this approach for acoustic compliance testing of a wind farm. The use of a regression analysis method developed more than 20 years ago is questioned. Anomalies with respect to compliance procedures and the regression method of analysis based on real-world experience are discussed.

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Section: Fundamental Issues With Acoustic Compliance Testingmentioning

confidence: 99%

Determination of Acoustic Compliance of Wind Farms

Cooper

Chan

2020

Acoustics

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“…Since the aerodynamic reference sound sources generate wind, it is common for windscreens to be used. The effects of the windscreens in sound pressure measurements were presented by Hessler [Hes08] and in intensity probes by Jacobsen [Jac94]. A numerical investigation on the use of windscreens was performed by Juhl [Juh06].…”

Section: State-of-the-art In Sound Power Measurementsmentioning

confidence: 99%

Investigation on the dissemination of unit watt in airborne sound and applications

Brezas¹

2019

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Sound power is a widely applied quantity for the characterization of sound sources. Its determination is based on measurements of sound field quantities. Despite the state-of-the art measurement techniques, the sound power determination has some disadvantages. Most significant is the low frequency limitation, with different measurement methods leading to different results, which are expressed in broad frequency bands. A new method is proposed towards the establishment of traceability in airborne sound power. The realization of a primary source enables the free field sound power to be determined. The study investigates the dissemination process by which the sound power of a device under test can be referred to its free field sound power. In addition, the related uncertainty can be explicitly determined. The method of choice is the substitution method, which has been investigated both theoretically and experimentally. Apart from the well-established sound pressure measurements, the implementation of the substitution method also includes sound intensity measurements. The theoretical investigation focuses on the different positioning of the sources used in the substitution method, the substitution of sources of different radiation order and the existence of an impedance boundary. The sound power of aerodynamic reference sound sources has been examined since this type of source has been chosen to be the required transfer standard. For the measurements a specially designed scanning apparatus has been used. Sound power determination in calibration conditions and in situ has been performed. The required correction has been derived and successfully compared to an existing one. Sound pressure and sound intensity measurements at realistic environments have taken place and their sound power has been determined by applying the dissemination process. The sound power determination includes both narrow and broadband analysis along with a transparent uncertainty budget for the spectrum from 20 Hz to 10 kHz. After the geometric near field, the far field starts and may extend to infinity. In this field the particle velocity and sound intensity have only radial components, and sound pressure and particle velocity are spatial angular [Fah95]. The far field exists when three criteria related to the distance approximately from the source, the wavelength and the characteristic source dimension are fulfilled [Bie03]. In the far field, the sound power can be determined along with the directivity. These two quantities can fully describe a sound source in terms of its radiated energy. This comes in contradiction to the characterization of the source based only to its characteristics. To overcome this contradiction, the present study proposes the characterization of the sound source based on its free field sound power, which is independent from the acoustic environment. Anechoic or hemianechoic rooms are qualified chambers, where free field occurs. In spite of determining sound power in such rooms, it is not possible for any source of intere...

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“…The outdoor and indoor SPL measurements were logged on a 1-min interval continuously for approximately 10 min, using the Larson Davis Model 831 sound level meter with Class-1 random incidence prepolarized condenser microphone (50 mV/Pa nominal sensitivity), preamplifi er (PRM831), and a one-third octave band analyzer fi lter set. After correcting for windscreen attenuation, [14] the one-third-octave band spectral Leq values were summed into three wide bands: An un-weighted Leq including 6.3 Hertz (Hz) through 16 Hz (representing an infrasound range), an un-weighted Leq including 20 Hz through 250 Hz (representing a low-frequency range), and an A-weighted LAeq including 6.3 Hz through 3150 Hz (a broadband A-weighted range). The Leq, or A-weighted Leq (LAeq), are used to describe the equivalent continuous level, which can be better thought of as an average level, for a certain period of time.…”

Section: Short Duration Sound Level Monitoring In and Outside Homesmentioning

confidence: 99%

Evaluation of community response to wind turbine-related noise in Western New York State

Magari¹,

Smith

Schiff³

et al. 2014

Noise Health

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As the boundaries of harvesting wind energy expand to meet the ever-increasing societal energy demands, the number and size of wind turbines being constructed rises. As part of a larger project to monitor sound in an operating wind park in western New York State, a cross-sectional survey was conducted among individuals living in and around the wind park to characterize the perception, level of annoyance, and self-reported health effects of residents. We conducted the study in a 126 MW wind park consisting of 84 turbines spanning approximately 19 square miles of farmland. Short-term outdoor and indoor sound level measurements were also performed at each dwelling in which a questionnaire was administered. To our knowledge, this study is the first to collect sound measurements at individual residences. There was no apparent exposure-response relationship between an individual's level of annoyance and the short duration sound measurements collected at the time of the survey. There was a correlation between an individual's concern regarding health effects and the prevalence of sleep disturbance and stress among the study population. The siting process is unique to each community with varying degrees of success. Additional sound level measurements inside and outside homes in larger cohorts in concert with detailed questionnaires would be useful in verifying those exposure-response relationships found in studies using calculated sound level data. Additional research should include a detailed investigation of sleep patterns and possible disturbance in those living in and near operating wind turbine projects.

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Experimental study to determine wind-induced noise and windscreen attenuation effects on microphone response for environmental wind turbine and other applications

Cited by 9 publications

References 0 publications

Determination of Acoustic Compliance of Wind Farms

Determination of Acoustic Compliance of Wind Farms

Investigation on the dissemination of unit watt in airborne sound and applications

Evaluation of community response to wind turbine-related noise in Western New York State

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