Spatial Sound Synthesis Framework for Computer-aided Composition.



OMPrisma is a library for spatial sound synthesis in the computer-aided composition environment OpenMusic. In addition to working with pre-existing sound sources (i.e. sound files) it permits the synthesis of sounds with complex spatial morphologies controlled by processes developed in OpenMusic in relation to other sound synthesis parameters and to the symbolic data of a compositional framework.
OMPrisma’s system architecture separates authoring of spatial sound scenes from rendering and reproduction (see the ISASA2010 paper). This approach provides an abstraction layer which allows the rendering of alternative realizations of the same spatial sound scene description using different spatialization techniques and loudspeaker arrangements.

Figure showing an algorithmic spatialization process with 100 individual sources and trajectories. a) number of souces, b) durations in seconds (looped), c) source soundfile, d) gain as a function of duration scaled by startposition, e) startposition, f) function for trajectory generation


Reproduction & Auralization

In addition to the authoring and rendering of spatial sound scenes, a third component of the OMPrisma framework is dedicated to aspects of reproduction (decoding, diffusion) – which often requires tweaking and adaptation for a given venue. For flexible adjustments in realtime we have developed two open-source MaxMSP-based standalone applications:

  1. The “MultiPlayer” allows decoding of Higher-Order Ambisonics files and provides functionality for compensation of time-delay and amplitude differences between loudspeakers.Multiplayer
  2. The “Binauralizer” allows for binaural reproduction/simulation via HRTF convolution with virtual loudspeaker in 6 D-O-F (positions and orientations) + room-model. A graphical “listener” representation can be moved and oriented with the mouse in real-time.  BinauralizerScreen Shot 2020-12-16 at 02.29.26