First-order superdirectional acoustic zooming in the presence of directional interferences

Acoustic zooming aims at increasing and decreasing the perceived distance of the sound-image by varying a zoom-parameter. Previously proposed superdirective acoustic zooming techniques focus on controlling the directivity-factor of the constructed beampattern by varying this zoom-parameter. As a result, these zooming techniques are only consistent in the case of (spherically) isotropic interferences. In practical situations however, often directional interferences (mainly coming from a single direction) are present. To have a consistent behaviour of the acoustic zooming, we will propose a new zooming technique that is based on a novel first-order beampattern construction. The beampattern is constructed in such a way that for every angle, the response is monotonically increasing/decreasing in a consistent way with the zooming-parameter.