Extraction of exterior field from a mixed sound field for 2D height-invariant sound propagation

Abstract

Any sound field caused by one or more sound sources takes the form of an interior or an exterior sound field based on the source location. The representation of the interior or exterior sound field in terms of harmonics decomposition has been extensively studied in the literature. However, the interior and exterior sound fields often co-exist in nature to form a mixed wave field. The extraction of the exterior sound field from such a mixed field can be very useful in many acoustic processes, which is yet to be explored extensively. In this paper, we discuss a method to extract the exterior field from a mixed sound field for 2D height-invariant sound propagation. Such an extraction method can be employed to record a sound field in a noisy or interfered room or to perform dereverberation in a reverberant room where the sound fields due to the source signal and its reflections superimpose each other. We demonstrate two practical uses of the proposed method in the forms of (i) an exterior sound field recording in a mixed wave field and (ii) speech dereverberation in a simulated reverberant room.