First off, welcome to the Resource
You can unpack PAC1.bin using
Vash's unpack tool. PAC0.bin needs to be in the same directory as that holds the file names and such.
Once you've unpacked, the audio files will be AT3 files. I haven't tested it but with luck you should be able to convert them using
VGSC.
To make AT3 files yourself, I think
this tutorial should work. If not you can maybe find some other methods for it elsewhere.
And to repack the files, use
Vash's repacking tool.
I haven't tested any of this myself, but give it a shot yourself.
(I should probably give credit to
this page by the way, for links to the un/repacking tools and other info.)
By the way, since this is about audio, could someone please move this to Ripping Help of the TSoR section?