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 I take a look after a newer version of this plugin 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