Ray-tracing and image-source methods fail on low-frequency diffraction at corners

Evidence

In a room with a complex shape, both image-source and ray-tracing methods are problematic at low frequencies. Features like corners, object edges, and curved surfaces exhibit phenomena, such as diffraction, that are not easily simulated with these techniques. Different element-based techniques are more accurate in such cases. The finite-element method (FEM) (Thompson, 2006; Zienkiewicz and Taylor, 1977) assumes the space is a set of finite-sized elements having mass, spring, and damping properties. Given the geometry of a room and the sound source(s), the sound field at any point can be solved. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 304

Categorization

• DEFINE: Introduces FEM and explains why it beats geometric methods where diffraction matters.