I have dealt with it by installing a solid door at the end of the hallway.
Read the comments on SuperUser. He's a single dad. Being unable to hear what your 4 year old kids are up to is a bad idea when there's no one else to monitor them.
I was recently talking to my boss, and my dad confirmed this, it is absolutely true that when suddenly the kids are quiet that you start worrying as to what they are up to =)
Yeah, my experience as a father has been the same. When it gets quiet, it may mean your kid is no longer playing with his toys and instead has just pulled up the floor vent to chuck his poop filled diaper into your ventilation ducts. Fun times.
Read the comments on SuperUser. He's a single dad. Being unable to hear what your 4 year old kids are up to is a bad idea when there's no one else to monitor them.