O. Thiergart, G. Del Galdo, M. Taseska, and E.A.P. Habets
Published in the IEEE Transactions on Audio, Speech, and Language Processing, 2013.
Traditional spatial sound acquisition aims at capturing a sound field with multiple microphones such that at the reproduction side a listener can perceive the sound image as it was at the recording location. Standard techniques for spatial sound acquisition usually use spaced omnidirectional microphones or coincident directional microphones. Alternatively, microphone arrays and spatial filters can be used to capture the sound field. From a geometric point of view, the perspective of the sound field is fixed when using such techniques. In this paper, a geometry-based spatial sound acquisition technique is proposed to compute virtual microphone signals that manifest a different perspective of the sound field. The proposed technique uses a parametric sound field model that is formulated in the time-frequency domain. It is assumed that each time-frequency instant of a microphone signal can be decomposed into one direct and one diffuse sound component. This decomposition can be performed using recently proposed signal-to-diffuse ratio estimators. It is further assumed that the direct component is the response of a single isotropic point-like source (IPLS) of which the position is estimated for each time-frequency instant using distributed microphone arrays. Given the sound components and the position of the IPLS, it is possible to synthesize a signal that corresponds to a virtual microphone at an arbitrary position and with an arbitrary pick-up pattern. The presented performance evaluation demonstrates the applicability of the proposed technique in a reverberant environment.
Blind source extraction using a rotating virtual cardioid microphone:
Blind source extraction using virtual spot microphone moving from the female speaker to the male speaker:
Dereverberation using virtual hyper-cardioid microphone:
Stereo recording using two rotating cardioid microphones: