What Is Sound Occlusion?

Sound occlusion refers to the way sound waves bounce around spaces and move past obstacles.

Virtual reality is getting more and more accurate as developers find ways to simulate the complexities of the world we live in. One of the more difficult problems they face in gaming and technology is sound occlusion.

Definition

Sound occlusion is the blocking of sound by large objects between the sound source and the listener. As we all know from experience, this blocking is not complete, as with light. Instead, sound flows around obstacles to come from different directions with different amounts of muffling.

Difficulties

Simulating sound occlusion is not as simple as rendering graphics. To tell when your view of something is blocked, programmers can use simple ray casting, following a straight line (or ray) from camera to object to see if the path is blocked. Sound, however, can move around obstacles.

Solutions

In general, developers ignore this problem, as the solutions are very costly in computing power. One method for simulating sound occlusion is to render a rough model of the 3d shape of the virtual room and use it to simulate sound wave propagation.

References

• Hal Archives: Fast Rendering of Sound Occlusion and Diffraction Effects for Virtual Acoustic Environments
• INRIA: Fast Sound Diffraction and Occlusion Effects