A two-channel feedback active noise control system with delayless subband architecture to reduce compressor noise of an enclosed heating, ventilation and air conditioning unit

Abstract

This paper discusses the development of an active noise control (ANC) system to cancel compressor noise produced by a commercially available heating, ventilation and air conditioning unit enclosed within a closet. Feedback ANC architecture that requires no reference microphone is used for cost-effectiveness. A novel delayless subband adaptive filtering technique is used to reduce computational complexity of the algorithm and improve system performance. Finally, the system is extended to two-channel architecture in order to provide an additional zone of silence. Using an experimental setup, the noise from the compressor at two error microphone positions is recorded and all necessary secondary path measurements are taken. Noise attenuation levels of 11 dB and 21 dB are obtained at the two error microphones, resulting in an average attenuation of 18 dB.