HEYYYYY ETHAN!!!!!!!!!
I would explain it to you dude but I can only absorb so much of ethan winers knowledge and......well it just sounds better from him. OK ill give it a try. Basicly, you need a material dense enough to slow the sound waves and turn them into heat to be able to stop them. I dont think pillow material(what ever it may be) would be dense enough to do so.
Stockton