Reproduction of nearby sources by imposing true interaural differences on a sound field control approach

In anechoic conditions, the Interaural Level Difference (ILD) is the most significant auditory cue to judge the distance to a sound source located within 1 m of the listener's head. This is due to the unique characteristics of a point source in its near field, which result in exceptionally high, distance dependent ILDs. When reproducing the sound field of sources located near the head with line or circular arrays of loudspeakers, the reproduced ILDs are generally lower than expected, due to physical limitations. This study presents an approach that combines a sound field reproduction method, known as Pressure Matching (PM), and a binaural control technique. While PM aims at reproducing the incident sound field, the objective of the binaural control technique is to ensure a correct reproduction of interaural differences. The combination of these two approaches gives rise to the following features: (i) an accurate reproduction of ILDs is achieved at the head positions considered by the method, (ii) the ILD variations in the vicinity of those positions are smoothed, thus lowering the ILD error, and (iii) the true wavefront is preserved. Given the properties of the presented method, intended distance and directional perception is expected.