This is where I come in.
The file format for the PlayStation originals of Twisted Metal 1, 2, and even the latter PSX games that we don't much like to talk about often here is the standard PlayStation sound formats.
The file you want to look for is UACORE.VAB in this case for Twisted Metal 2 PSX.
The extension .VAB, Virtual Audio Bank for short, contains .VAG files which are the PlayStation's proprietary PCM audio files for each sound effect and whatnot.
.VAG files (I don't know the abbreviation for this one but LOL VAGina so funny immature joke sorry haha) iirc also sometimes contain looping data. For example: the turbo sound. But my memory could be shit, and that could actually be in the .VAB
Come to think of it, and I apologize for my rambling. I've noticed sometimes that some of the sound effects are comprised of multiple .VAG files, playing at different tempos and pitches and whatnot E.G. Sweet Tooth's firing sound, or Dark Tooth's firing sound.
There's also .VB and .VH files which aren't present. But they exist for other purposes with other games.
I'd recommend researching those in particular, there's already leaked Sony tools that work perfectly, but if you could reverse engineer them and make them work on modern OS' and make them cross-platform? You'd kick serious fucking ass, needless to say.