Reconstruction of the Sound Field in a Room Based on Wavenumber Processing

In recent years there has been a growing interest in the spatial characterization of the acoustic field in rooms and enclosures, aimed at sound field analysis, control, and reproduction. In order to obtain a full spatio-temporal characterization of the sound field, the pressure field is typically measured point-by-point using sequentially phased measurements (or an array of transducers). In the present study we propose a method to reconstruct the sound field inside a room. The
method is based on expanding the sound field in wavenumber domain, from measurements with a spatially-distributed array of microphones. The modal structure of the sound field is examined, and the accuracy of the reconstruction at low frequency is assessed. The method makes it possible to extrapolate the sound field in the three-dimensional space contained in the room’s volume. Results in a small rectangular room and a larger non-rectangular room are presented.