Close-Talking Recording With Planarly Distributed Microphones

This paper provides a close-talking recording method with planarly distributed microphones based on sound pressure interpolation. In the proposed method, sound pressures recorded by microphones located close to the center of multiple co-centered circular microphone arrays are interpolated by sound pressures recorded by the arrays based on multiple 2D cylindrical harmonic analyses. If sound sources are outside the spherical boundary with the maximum radius of the arrays, the interpolation is completed. On the other hand, if sound sources are inside the spherical boundary, the interpolation is not completed in principle. By using the principle, close-talking recording can be realized as the residual response between the recorded and interpolated sound pressures. The recording radial sensibility can be controlled by changing the maximum radius of the arrays. By introducing kernel ridge regression-based sound field interpolation method, the proposed approach can be extended to the method with planarly distributed microphones. The results of computer simulations indicate the effectiveness of the proposed close-talking recording methods.