Fast acoustic obstruction with proximity cost differencing (PCD)
- Keith Godin ,
- Nikunj Raghuvanshi
AES International Conference on Audio for Virtual and Augmented Reality |
Organized by Audio Engineering Society
Acoustic obstruction is a difficult challenge faced in virtual reality and games. Obstruction is the loss in audio loudness due to objects and doorways that intervene the line-of-sight between a sound source and listener. Visual obstruction using a single ray-cast is fast to compute, but too abrupt for audio, sounding obviously unrealistic. On the other hand, using a full wave simulation is accurate but computationally expensive, requiring pre-computation. In this paper, we try to balance the two extremes with a new heuristic approach (PCD) that is orders-of-magnitude faster than wave simulation and shows promise for evolving into a real-time technique. We show that PCD captures the qualitative behaviors expected from wave diffraction.
![](https://www.microsoft.com/en-us/research/uploads/prod/2020/07/PCD.png)
The proposed PCD algorithm for acoustic obstruction (middle row) is able to capture the qualitative variations from a small aperture compared to reference FDTD (bottom row) at more than 100 times speedup. In comparison, simple heuristics used in games today (top row) produce unrealistic results where a small pinhole can still transmit a large amount of energy, which results in easily audible artifacts.