408 Active Noise Control for 3-Dimensional Sound Field Using Fast Converging Algorithms

Active control in 3-dimensional sound field against incoming noise from external noise source is considered. Convergence characteristics are investigated with not only conventionally wide-used Filtered-x LMS algorithm, but also FTF (fast transversal filter) and FDA (frequency domain adaptive) algorithms. The advantages and disadvantages of each technique are examined through simulations and experiments using 1/5 scale model. Control results are studied also with both fixed noise source and moving noise source, and the difference in the control performance of each algorithm is compared and considered. As a result of simulations and experiments, it is shown that the control performance of FTF and FDA are better than it of LMS for the fixed noise source. For the moving noise source, each performance of control becomes worse; however, it is shown that control can be continued comparatively stably.