The SoundCollectionDef schema is defined in sound_collection_def.fbs. Individual SoundCollectionDefs are defined in the sounds/ subdirectory, one SoundCollectionDef per file. SoundCollectionDefs are the primary method of playing audio through the AudioEngine.

A SoundCollectionDef, as its name suggests, is a collection of related sounds. For example, you may have multiple samples of a foot step, or songs you would like to randomly select to play on a menu screen. A trivial SoundCollection may contain only a single audio sample. Sample playback probability may be weighted to give preference to certain samples. Each SoundCollectionDef must have a unique identifier, and must have been loaded by a SoundBankDef prior to being played.

The SoundCollectionDef schema also specifies a number of other fields which are documented in the schema itself.