We present a new interaction handling model for physics-based sound synthesis in virtual environments. A new three-level surface representation for describing object shapes, visible surface bumpiness, and microscopic roughness (e.g. friction) is proposed to model surface contacts at varying resolutions for automatically simulating rich, complex contact sounds. This new model can capture various types of surface interaction, including sliding, rolling, and impact with a combination of three levels of spatial resolutions.  We demonstrate our method by synthesizing complex, varying sounds in several interactive scenarios in a game-like virtual environment. The three-level interaction model for sound synthesis enhances the perceived coherence between audio and visual cues in virtual reality applications.