I watched the "dog whisperer" and he has nothing on me. Training a dog is easy. The dog is easy; it's people who need training. Most dogs respond to gentle correction. That is why the guy whispers. Even children listen better if you whisper.
When I taught high-school, if a student was being noisy, I would go to his or her desk, and place a sticky note on the desk. The note would read, Sh!
It was affective and always brought a grateful smile to the young person's face. Sometimes humor and whispers are better deterrents to bad behavior than screaming. Just a thought.