A Simplified Method for Determination of “Amplitude Modulation” of Audible and Inaudible Wind Turbine Noise
* Presenting author
The operation of a wind turbine results in a series of pulses where there is a significant 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.