Poker room, only sharing 2 walls?

[Pokerguy]

I have moved into an apartment and want to turn a back room into a poker room. Obviously its too loud.  I only share two walls with other apartments. we live on the top apartment and below us is not a problem either, so do i need to soundproof all the walls or just the two that i have in common with other apartments? 

Also what is the best value for money remedy for my situation, it will mainly have to insulate against voices and maybe a bit of music, but voices is my main convcern.

[Randy S]

A second layer of drywall with green glue will do the trick, but since you rent this might not be an option.
http://www.soundproofing.org/ggpages.htm
If you cant modify the wall then the only other suggestion would be to use Fabtec panel and cover both walls. http://www.soundproofing.org/sales/flameresistant.htm
This will absorb some the noise in the room and reduce some of the noise passing through the walls. The panels will not stop the noise just reduce it.