Verification of a near-field error sensor placement method in active control of compact noise sources.

Recent experiments in active noise control (ANC) have used near-field error sensors whose locations are determined according to the minimization of sound power. Sensors should be placed in regions where the sound pressure reductions are the greatest during sound power minimization of the ANC system. Near-field pressure measurements of noise sources with and without ANC were made. With the error sensors in theoretically ideal locations, the measured near-field pressure map approximates the theoretical map created under the condition of minimized radiated power. Moving the error sensors to theoretically nonideal locations greatly reduces the attenuation of radiated sound power.