XWB Extractor will parse your XWB files and extract the embedded files.
These files can be of any type, but I've found sound files PCM and WMA.

Source isn't included in this release because I'm not sure if one of the files
I use can be released to the public.

This program has been tested on Burnout 3, Metal Slug 3, and Prince of 
Persia: Warrior Within.

I've received requests about BIG, MUS, and AWD files.  From what I've found, 
some EA games use BIG files with BIG4 as the first 4 bytes, and some have the
first 4 bytes as 05 00 00 00.  The BIG4 ones look to have ASF files in them,
because they have tags of SCHl, which is the ASF header.  MUS files look like
they have ASF files and BNK files, which I would guess is a sound bank file,
maybe in a MIDI format.  Don't know what app uses a BNK file.

If anyone has info of these file formats, please email me at 
lee_hamel@yahoo.com and I'll include support in a future release.