Are the kids in pack n plays in those room so they are 'contained'?

I just use one monitor upstairs and put it in the hallway and leave the bedroom doors open a crack so I can listen on the monitor and do a visual peek in the door every so often as well...mind you my house is small if someone is crying I can hear it without the monitor - the monitor is more for catching them 'waking up' before they get to the distressed and crying to let you know they are awake.