Exploring feedback active noise control with ambisonics

Excessive undesired acoustic noise interferes with normal daily human activities and hence, it needs to be controlled and alleviated. With efficient and powerful computational capability of digital technology, recent adaptive active noise control (ANC) research has seen its way into consumer electronics, automobiles and recreational applications. Unlike Feedforward ANC methods, Feedback ANC methods require no direct measurement of the source noise making them more cost-effective and more suitable for use in large 3-dimensional acoustic environments with multiple noise sources. In this paper, we propose the use of spatial advances made in Higher Order Ambisonics (HOA) technology to attenuate localized noise sources and extend the quiet zone in a large area using multi-channel Feedback ANC architecture. We show that the use of Ambisonics soundfield microphones improves updating of the adaptive algorithms for parallel processing and real-time implementation in the proposed ANC system. The proposed ANC system can be used to control the noise in large acoustic enclosures such as museums and concert halls.