Ripping sounds from Gex 2

[souperzombie]

So after some furious googling I've managed to find my way into the .bigfile that all the Gex 2 sound files are located. However when looking through them in PSound all the voice lines, which are the ones I need, all seem to have the same filename (C:\gex3d\sounds\ ,even though that's a directory and not a filename), which means I can't convert them without the files overwriting themselves, and the sound files stop playing after about a second or so both in PSound and in a media player, so the files seem to be incomplete.
This is pretty much my first time trying something like this, so I don't really know what to do from here. If it means anything I've attached one of the converted sound files, and I'm using the UK/PAL version of the game.