you could record them, and try out some voice removal tools.
Edit:
Lol I tested it right now..and it works suprisly great..The quality is bad, and its mono..but check out youself.
THESE are cutscenes audio files from GF and they contain spoilers!
I used the winamp 2 dsp effect / plugin "voice removal"
The plugin is "Nullsoft DSP Effects Plug-in 0.35 for Winamp 2"
The "lola scene " bgm is pretty amazing without the voice.
But check out yourself..
gf_cs.mp3 (
www.sal4.de/new/gf_cs.mp3) original
gf_cs_vr.mp3 (
www.sal4.de/new/gf_cs_vr.mp3) voice removal
Both are about 3,5 mb big :)
I take a look after a newer version of this plugin
dsp_ns.ace (
http://www.sal4.de/new/dsp_ns.ace)
I noticed it works much better if you use wave files instead of comprimised mp3s
( the files will be up in about an hour, so one hour later after I reply ;)
Arthur