Obstruction

Obstruction, in interactive audio, describes the case where a solid object blocks the direct path between a sound source and the listener while indirect paths around it remain open. The direct sound is reduced and filtered, but reflected and diffracted energy still reaches the listener, so the source sounds muffled yet clearly present.^[1]

Audio engines model obstruction by lowering high frequencies and level on the blocked direct path while preserving the reverberant component, which mirrors how sound bends around obstacles in the real world. Handling it well gives players a believable sense that a source is hidden behind something rather than sealed away entirely.^[2]