CBX file

.CBX files, also known as chatterbox files, are audio files, stored in a proprietary audio compression format. Lego adaptation games use the format primarily for voiced lines, including grunts.

Here is an example of CBX file from Lego Batman 2. It (probably) contains Bane's hub boss intro line. https://cdn.discordapp.com/attachments/539431630310211587/721468599159619774/dx_bane_whatever_ENG.cbx

Almost of the voice grunts in Lego The Hobbit have WAV counterparts alongside their CBX files; this may prove useful for someone who wishes to reverse engineer the format.

Files that use CBX compression are clearly marked as such in audio.cfg. As such, it is not pressing that we reverse-engineer how to encode a CBX file, so long as we can decrypt how to decode a CBX file.