Close-Talking Recording with Planarly Distributed Microphones

Abstract

This paper provides a close-talking recording method with microphones in arbitrary planar distributions based on sound pressure interpolation. In this method, sound pressures recorded by microphones located near the center of multiple co-centered circular microphone arrays are interpolated using sound pressures recorded by these arrays via multiple 2D cylindrical harmonic analyses. If the sound sources are outside the spherical boundary formed by the maximum radius of the arrays, the interpolation is completed. However, if the sound sources are inside the spherical boundary, the interpolation is not completed in principle. Using this principle, close-talking recording is realized as a residual response between recorded and interpolated sound pressures. The recording radial sensitivity can be controlled by varying the maximum array radius. By introducing a kernel ridge regression-based sound field interpolation method, the approach can be extended to the microphones in arbitrary planar distributions. Simulations confirm the effectiveness of these close- talking recording methods.