Ripping PlayStation 2 voice clips

[tanooki426]

UPDATE: I finally figured out how to extract PSS files from PlayStation 2 games! However, when I attempted to use PSS Plex to extract the audio from the cutscenes of Ben 10 Alien Force: Vilgax Attacks, I got video files but no audio. I changed to another utility and got the same result: video but no sound. What's going on?