An acoustical zoom based on informed spatial filtering

In digital cameras, zooming allows for narrowing the apparent angle of view in a video or an image. When sounds compliment the visual information, a desirable function would be to provide an acoustical zoom which is aligned with the zoomed visual image. In this paper, an approach is presented to achieve such a zoom effect using a microphone array. Acoustical zooming is realized by a weighted sum of the extracted direct sound and diffuse sound, whereas the weights depend on the zooming factor. The proposed approach uses two recently proposed informed multi-channel filters for the extraction of the direct sound and diffuse sound. Simulation results indicate that the performance is good even in challenging double-talk scenarios.