Best/Cheap way to sound proof a pet room (crating a puppy)?

Hey all, I recently bought an 8 week old puppy and I'm currently in the process of crating him. I'm being told that if I crate him and keep his crate next to me, he will not be able to be alone for while I'm at work ( I work nine hour shifts, but come home at lunch, so he will only be alone for 4 hours at a time). I currently live in an apartment and am trying to sound proof his "room." His room consists of a giant walk-in closet. I was told by some people to put up carpet tiles, egg cartons and even the pink foam boards. I did like the closet with the pink foam boards and I could still hear him pretty well. I dont mind if I hear him, I just don't want to tick off the neighbors. Anyone have any cheap sound proofing ideas/suggestions or know how to crate a puppy fast? I'm even considering going to a relatives how and just staying there a week for the duration of the crating nights.