A generalized approach to modal filtering for active noise control. II. Acoustic sensing

For pt. I see ibid., vol.2, no.6, p.577-89 (2002). Scaling laboratory-sized active noise control systems into industrial-sized implementations is a difficult exercise. Problems relating to sensing system design account for some of the difficulty. In the first part of this paper, an alternative approach to sensing system design was presented where acoustic radiation patterns are decomposed using fundamental acoustic quantities, rather than structural modal based quantities. In this paper, the approach is tackled in the acoustic domain instead of structural vibration. The technique has been simulated in the time and frequency domains using acoustic sensors and implemented experimentally.