Conversion of Discretely Sampled Sound Field Data to Auralization Formats

摘要

Sound field simulations at low frequencies often use finite-element or other mesh-based methods. For auralization, output data from these methods need to be converted to a format compatible with auralization methods, such as binaural reproduction, wave field synthesis (WFS), higher order Ambisonics (HOA), or vector base amplitude panning (VBAP). The mesh data can be viewed as a spatial sampling of the sound pressure distribution. A method is proposed for converting the mesh data to plane-wave components using a circular array of virtual sources centered around a reference position. Such a plane-wave decomposition (PWD) is straightforward to process further for auralization. Emphasis is put on generalized modal decompositions of sound fields through singular-value decomposition, and on the relation between modal bandwidth and the ratio of mesh width to wavelength. The special case of a decomposition into cylindrical harmonics is studied in detail. Results are presented for two-dimensional examples, and numerical issues are discussed.