Measuring wind turbine infrasound in the presence of wind

A windscreen enables noise measurements to be made as accurately as possible under typical field conditions. Measuring wind turbine noise presents a greater level of difficulty than normal. For there to be wind turbine noise, there needs to be wind for the turbines to operate. Greater wind turbine noise is generally associated with higher wind speeds. Multiple windscreens have been found to significantly reduce artificial wind noise in the range of hearing of 20 to 20 kHz, but cannot reduce the very low frequency pressure fluctuations associated with the movement of air during gusts of wind or in the case of interior measurements fluctuations due to wind pressurizing the building. Wind turbines have been demonstrated by others to produce infrasound in the range of 0.5 to 10 Hz. Measuring infrasound in the presence of local wind is a challenge, since finding a less windy time is not an option. Area-wide measurements of wind turbine noise were conducted at two wind turbine facilities. In analyzing the recor...