The Design of Wind Noise Transducers to Separate Acoustic and Turbulent Pressures

A four element wind noise transducer has been designed with surface mounted electret microphones in an array pattern which allows for the separate determination of the acoustic and turbulent pressures in wind noise. Three closely spaced transducers, defining an x-y coordinate system, are positioned to determine the velocity and direction of the turbulent flow. A fourth transducer is positioned at a greater distance such that the correlation of the turbulent flow will be diminished while the correlation of the acoustic pressure remains due to its longer wavelength. By averaging the cross-spectral densities of the pressure signals over time, the two contributors to wind noise can be differentiated. In addition, a wireless interface has been designed to minimize the flow disturbance of the transducer array.