Small audio files can be embedded directly within TiddlyWiki. Embedding isn't suitable for large files (over a few hundred kilobytes) because it increases the size of the TiddlyWiki file.
For example, the tiddler [[TiddlyWiki.mp3]] contains an MP3 recording of the word "TiddlyWiki". Viewing the tiddler directly should show an audio player that allows playback.
External audio tiddlers use the ''_canonical_uri'' field to point to an external audio file/stream, and have a block ''text'' field. This reduces their size considerably, and still allows for playback.