Let the hive mind of Engadget get that for you.
"I need help! I want a small pocket camcorder but I'm not sure which one to get. I don't want to fall into the hype of the Flip because I worry two hours won't be enough. What should I be looking for when considering a small camcorder and where can I get a good quality one with expandable memory? Thanks!"
I'm sure the home owner who is buying a 2000 dollar sound proof door, also thought to sound proof the rest of the room.
What for? Maybe leave the windows opened so you can hear all the traffic and construction work going on in your hood. Or, perhaps the door is designed to block the screams of kids and family members visiting from out of town.