Virtual Sensor for Multichannel Real-time Active Noise Control

The ultimate goal of active noise control (ANC) system in a three dimensional noise environment is to create a zone of quiet at target location. Generally, the quiet zone with best noise cancellation is achieved at the locations of error sensors, thus the distribution of physical error sensors should be close to the desired location, which might not always be a convenient or feasible solution. Virtual sensor is a method to overcome this problem. In this paper, an adaptive least mean square (LMS) virtual sensing algorithm is applied to estimate the error noise signal at virtual location. A multichannel real-time ANC system with virtual sensor is then designed to enhance the zone of quiet at target location. The resulting quiet zone is measured by a sound pressure level (SPL) meter; it proves that a zone of quiet with enhanced noise attenuation is successfully generated at the desired location.