In this case, the distribution of the acoustical energy in the 3D space requires a set of fixed loudspeakers precisely- and accurately-controlled. The physical approaches used so far in this context have involved modelling sound fields using physical models based on propagation equations. Two main approaches have been used so far for this purpose: the physical approach, where sound fields resembling real ones as closely as possible are simulated, and the perceptual approach, where the resulting perceptual effects are taken into account. Many authors have previously addressed these problems. To simulate motion, the speed and trajectories are crucial to creating realistic acoustical environments, and developing signal processing methods for reconstructing these contexts is a great challenge.
Virtual reality is another field, where moving sources play an important role. Although the effect of this motion on sound has not yet been clearly established, it probably contributes to the rendering and should be taken into account in attempts to synthesize musical sounds. have described, for example, that the motion of the clarinet follows specific trajectories depending on the type of music played, independently of the player.
Motion of instruments while they are being played can also subtly affect the sound, and hence the expressiveness of the performance. The simulation of moving sources is of great importance in many audio sound applications, including musical applications, where moving sources can be used to generate special effects inducing novel auditory experiences.