Skip to content

Environment Models

Environmental simulations play a crucial role in achieving realistic binaural audio rendering by replicating how sound interacts with its surroundings. These simulations model the acoustic behavior of spaces, including reflections, reverberation, and the effects of air propagation, to recreate an immersive auditory experience that closely resembles real-world scenarios. By combining environmental models with listener and source models, the BRT Library ensures accurate spatial audio reproduction.

What we call environment models in the BRT Library are models that simulate the propagation of sound in a given acoustic environment using geometric algorithms based on virtual sources. Currently, the BRT Library provides two environmental models:

  • Free Field Environment Model: Simulates direct sound propagation in open spaces, accounting for propagation delay, distance-based attenuation, and filtering effects caused by the medium.
  • SDN Environment Model: Implements room acoustics simulation using Scattering Delay Networks1, a computationally efficient algorithm for modeling reflections and reverberation in enclosed spaces.
  • ISM Environment Model: Simulates room early reflections using the Image Source Method in complex room shapes.
  • Hybrid approaches: The BRT Library does not implement hybrid reverberation as a single monolithic model. Instead, hybrid rendering strategies can be achieved by combining multiple high-level modules. A common hybrid configuration consists of:
    • An ISM Environment Model to generate early reflections as virtual sources.
    • A BRIR-based Listener Model to reproduce the late reverberant field through convolution.

      This approach reflects the modular design philosophy of the library and allows independent control of early and late reflection processing.

And we are working to incorporate the following:

  • Amibisonic Reverberation : (Under Development)

  1. de Sena, E., Hacihabiboglu, H., & Cvetkovic, Z. (2011, February 2). Scattering Delay Network: An Interactive Reverberator for Computer Games. 41st International Conference: Audio for Games. ↩