Audibility of reduced spatial resolution in musical instrument directivity

The directivity of sound sources plays an important role in the generation of auralizations. Researchers have invested a considerable amount of time and effort in generating directivity databases of musical instruments with high levels of detail. However, it is still unclear how precisely these data should be captured and modeled with respect to perception. Therefore, investigating if simplified patterns with lower spatial resolutions are perceptibly different from higher-resolution patterns provides valuable insights into determining the spatial resolution required for perceptually significant measurement and modeling of directivity patterns. In this study, we present a listening test that investigates the spatial resolution of the magnitude of directivity patterns using different spherical harmonic orders of two musical instruments (a trumpet and a flute) in two listener positions and rooms. Apart from changing the resolution for the entire simulation, we also tested hybrid responses for one of the rooms, where the order was modified only for the direct sound or the early reflections.