Cancellation, reproduction, and cloaking using sound field control

Abstract

The active control of sound fields has been applied in active noise cancellation, sound field reproduction, and active acoustic cloaking; however, relatively few studies have considered the relationship between these three areas of research. This paper investigates the physical limitations on active noise control, sound field reproduction, and active acoustic cloaking in terms of the controllability and observability of the sound field. This has been achieved through a series of simulations that consider the control of the sound field in the presence of a scattering object. In terms of the controllability problem, it is shown that while active noise control and sound field reproduction are most effective when considering the interior control problem, active acoustic cloaking is most effective when facing the exterior control problem. Different sensing strategies are then considered for the cancellation, reproduction, and cloaking problems and their impact on the observability of the control problem is discussed.