Complex point source model to calculate the sound field radiated from musical instruments

A simple method is described to record the radiated sound of musical instruments and to extrapolate the sound field to distances further away from the source. This is achieved by considering instruments as complex point sources. It is demonstrated that this simplification method yields plausible results not only for small instruments like the shakuhachi but also for larger instruments such as the double bass: The amplitude decays in a given manner and calculated interaural signal differences reaching the listener decrease with increasing distance to the source. The method can be applied to analyze the sound radiation characteristics as well as the radiated sound field in a listening region regardless of room acoustical influences. Implementations in terms of room acoustical simulations, spatial additive synthesis and sound field synthesis are discussed.