RESound: interactive sound rendering for dynamic virtual environments. We present an interactive algorithm and system (RESound) for sound propagation and rendering in virtual environments and media applications. RESound uses geometric propagation techniques for fast computation of propagation paths from a source to a listener and takes into account specular reflections, diffuse reflections, and edge diffraction. In order to perform fast path computation, we use a unified ray-based representation to efficiently trace discrete rays as well as volumetric ray-frusta. RESound further improves sound quality by using statistical reverberation estimation techniques. We also present an interactive audio rendering algorithm to generate spatialized audio signals. The overall approach can render sound in dynamic scenes allowing source, listener, and obstacle motion. Moreover, our algorithm is relatively easy to parallelize on multi-core systems. We demonstrate its performance on complex game-like and architectural environments.