Three-dimensional Acoustic Source Mapping

When beamforming is applied for acoustic source mapping, the sound pressure contributions of any sound sources are most often mapped to a planar or a surface map. However, some practical applications would benefit from a three-dimensional mapping, where the map consists of a three-dimensional grid. It is shown that the extension of microphone array beamforming techniques to three-dimensional mapping is straightforward in principle, but requires the mandatory use of deconvolution techniques. Feasible deconvolution approaches and their practical implementation are discussed. While the computational cost is considerable higher than for classical two-dimensional mapping, the three-dimensional approach provides a number of advantages and easily delivers correct information on the source level by using an adopted integration technique. Finally, the three-dimensional mapping is demonstrated and the results of practical applications are shown and discussed.