Evaluation of wind farm noise amplitude modulation synthesis quality 

Abstract – Wind farm noise amplitude modulation (WFN_AM) is a major contributor to annoyance and could cause sleep disturbance. In laboratory listening experiments assessing its annoyance and sleep disturbance potential, WFN_AM stimuli are commonly synthesised and can thus suffer from a lack of ecological validity. Here, five stimuli synthesis methods were compared with measured noise in terms of their perceived similarity. An ABX discrimination listening test and one-third octave band spectra were used for evaluation of the aural and visual similarity, respectively, between the synthesised and measured noise spectra. The results showed that synthesising WFN_AM using a simple method can be ecologically valid as listeners could not accurately differentiate between measured and synthesised WFN_AM. However, time varying features of WFN_AM do play a small but significant role in human perception and therefore hearing test evaluation of synthesis is recommended for obtaining the most ecologically valid synthesised WFN_AM.

Duc Phuc Nguyen, Kristy Hansen, College of Science and Engineering, Flinders University, Adelaide, Australia
Branko Zajamsek, Peter Catcheside, Adelaide Institute for Sleep Health, Flinders University, Adelaide, Australia

Applied Acoustics, Volume 166, September 2020, 107349.
doi:10.1016/j.apacoust.2020.107349

Download original document: “Evaluation of wind farm noise amplitude modulation synthesis quality”

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Wind farm infrasound detectability and its effects on the perception of wind farm noise amplitude modulation

ABSTRACT – Some residents attribute adverse effects to the presence of wind farm (WF) infrasound. However, dominant features of windfarm noise such as infrasound, tonality and amplitude modulation span the average human hearing threshold, so attribution to infrasound is problematic. This study used a combination of pre-recorded noise stimuli, measured at 3.2 km from a wind farm, in laboratory-based listening tests to investigate human perception of infrasound and amplitude modulation at realistic sound pressure levels in a group of 14 participants. Although a small sample size warrants cautious interpretation, preliminary results suggest differential effects between self-reported non-sensitive versus noise-sensitive participants, where the latter detected infrasound above chance. Infrasound did not affect the perception of amplitude modulation. Larger studies remain needed to clarify these findings.

Duc Phuc Nguyen, Kristy Hansen, College of Science and Engineering, Flinders University, Adelaide, Australia
Branko Zajamsek, Gorica Micic, Peter Catcheside, Adelaide Institute for Sleep Health, Flinders University, Adelaide, Australia

Presented at the Australian Acoustical Society Annual Conference, Acoustics 2019.

Download original document: “Wind farm infrasound detectability and its effects on the perception of wind farm noise amplitude modulation”