.XSB File Extension

Collection of sounds and cues created with Microsoft XACT, the Cross-Platform Audio Creation Tool; used for creating video game sounds and defining when they should be played in the game.

XSB files do not contain audio data, but instead references wave data stored in .XWB files. XSB files are used by various video games, such as Gas Powered Games programs, and are stored by default in the /Sounds directory.