Active noise control using adaptive digital signal processing

Active noise control utilizes microphones, electronics, and loudspeakers to generate an acoustical wave to cancel undesired sound. The basic approaches to active noise control are briefly reviewed. Primary emphasis is on a system identification approach to the problem using adaptive digital signal processing. A solution to problems caused by the acoustical nature of the application is presented. This includes a discussion of the use of an IIR (infinite-impulse response) adaptive filter to model the primary plant and compensate for acoustic feedback, the use of an independent random noise generator to continuously model the characteristics of the source and error plant, and the effect of uncorrelated noise on both processes