An investigation into the performance limitations of active acoustic cloaking using an acoustic quiet-zone

The use of active control to acoustically cloak an object has been demonstrated previously, and is effective if the scattered component of the pressure field can be measured and directly minimised. In practice, this is non-trivial as a pressure sensor in the sound-field will detect the superposition of the incident and scattered pressures. An alternative approach has been proposed in the literature, using high-order multipole sources to generate a zone of quiet around the scattering object, whilst not radiating into the far-field. This approach performs well, however the use of high-order multipole sources is infeasible for a practical implementation. This paper will explore the limitations of the quiet-zone acoustic cloaking strategy on simulated data of a rigid spherical scattering object, using a practical arrangement of monopole control sources and error sensors. The same arrangement of sources and sensors is also used to directly minimise the scattered sound field, and the two approaches are compared in terms of practicality, control-effort, and performance