Cooper, S. Hiding Wind Farm Noise in Ambient Measurements…. Denver August 2013
Hiding Wind Farm Noise in Ambient Measurements – Noise Floor, Wind Direction and Frequency Limitations
Steven Cooper, The Acoustic Group Pty. Ltd.
5th International Conference on Wind Turbine Noise, Denver 28-30 August, 2013
Apart from inadequacy of dB(A) measurement to identify the acoustic signature of wind farm noise the provision of averaging techniques by use of regression curves related to hub height wind speeds are of no assistance to the community in determining acoustic compliance. Furthermore the frequency limitation of various sound level meters automatically restricts the provision of appropriate noise data related to turbine operations. A further issue of concern relates to the noise floor of the measurement system that by the (intentional or unintentional) selection of microphones can render the measurements of no assistance. Examination of different analysis parameters, instrumentation frequency response and microphone noise floors is provided to identify the above anomalies.
The selection of acoustic descriptors used for general community noise assessments do not specifically address or cater for unique characteristics that may be exhibited in the acoustic signature that alter the subjective response to the noise. It is in response to unique characteristics to the noise that leads to a more detailed assessment to quantify the subjective impact. To the modern day acoustician, with the advantage of sophisticated instrumentation and advanced measurementt echniques, utilisation of the more detailed analysis is readily available yet often times ignored.