As you may know, in Bully, all the audio files are compiled into four seperate files. (ambs, cuts, music, and speech) .bin files.
If you decompile them, you can get ahold of the audio files themselves in .xsb/.xwb formats.
The only problem now being, no audio software can read this, so using a program called 'towav' you can convert them to .wav files which are readable by Windows Media Player.
Here's where importing new tracks and speech comes in:
As far as it's concerned, no-one knows of this being done yet.
The idea is simple, exectution is harder.
The main thought I had was simply reversing. You reverse what you did to decompile/extract, you would get them from .wav, to .xsb/.xwb, and then all into a .bin file.
The hard part about this is getting .wav files to .xsb/.xwb. Hard, but certainly not impossible.
I am currently working on getting this to happen. The perks of this will really help people in creating mods, allowing them to change the speech used in cutscenes, and the music used in certain situations.
The way you trigger music in lua will still work the same way with the same filenames, provided you don't change them.
I am also hoping to find a code to trigger certain speech when activated. (eg: when Jimmy slips on a banana, says "aw fuck" with the speech you imported)
Once this is finished, I am hoping to get help from someone I've spoken to, to help me out in creating a program similar to imgtool, but for sound files. So instead of it working with .img filetypes, it'll open .bin files, where you can place your .xsb/.xwb files of choice.
This could take some time, but I'm hoping to put a lot of effort into getting this to work.
Anyways, enjoy the rest of your day!
