The VG Resource

I'm doubting that anyone here can really help me with this, but I figured I may as well post my problem nonetheless.

I'm having issues converting these to regular formats. I've tried a number of programs, but for whatever reason none of them have worked. The only reason I know they DO work is because I've seen someone convert some of the files from this game already or at least its prequel. Specifically, I'm trying to convert .AT3 sound clips from Phantasy Star Portable 2 Infinity with no real luck so far.

If anyone could mention some methods I could try or a program I could use to convert these that would be amazing.

Edit: I guess I probably should have posted this in Sound Projects originally, but eh.

I can't remember exactly what I had used to rip Prinny's voice samples from their original AT3 format... I think it was HiMDRenderer.

Much appreciated, it works. Now only over 9000 (9265 to be exact) more sound files to go through, heh. Expect to see a full rip of the game fairly soon.

Edit: Okay well it works on some of the files, but apparently most of them use an unsupported bit rate. I'll need another program to convert a good lot of them.