I PM'd you.
16 kgm glass fiber would do the job if you are going to put it in between walls. Although the denser the glass fiber the better, in terms of sound proofing, the important thing to remember is the wall that will stop the sound. Thus, thicker, denser walls are better (yes, as jplacson said, heavier, better). Although solid concrete is definitely good, you can achieve the STC properties of concrete by doing a sandwich type wall. The glass fiber inside is there to prevent resonances inside the wall cavities, not to impede the sound. Hence, rolled glass fiber (cheaper) is okay. Also, better if you can make the wall thicker - by double the thickness of the wall and employing an air gap. Instead to using 2 inch walls, you can use 4 or 6" studding plus gypsum walls. Put one gypsum on one side and two on the other side. Glass fiber cut and placed in between the cavities. Caulk all butt joints. Stagger the placement of the gypsum wall board.
Foam and styropore are not recommended. Both are flamable and dangerous - toxic. Glass fiber is fine. No found evidence of it being carcinogen.
FWIW