Rhonda66 - To answer your question - YES! You can hear through the room, but the last time we had a connecting room where we did not know the people, all we ever heard were the kids. Their pitch seems to penetrate through anything....
Nothing against kids....have some of my own, but they do seem to get up earlier than me.
If you don't have a rowdy group, you probably will not hear anything. And even if you did have a rowdy group next to you and no connecting door, you still might hear them.
All in all, it wasn't too bad....very similar to a hotel connecting door.
Hope this helps