I hear ya. It's one thing to bring unruly kids to the restaurant you're dining in, but having them live next door is something different. I can only wish you the best, and recommend noise-cancelling headphones if it turns out to be a nightmare.
Actually, I just thought of something. You know those whistles that only dogs can hear? There's something similar for stopping unruly & antisocial children from loitering outside malls etc:
Here's a picture of one. They're called "Mosquito sirens":
OH. MY. WORD. They actually WORK! http://www.thetelegraphandargus.co.uk/n ... yob_siren/
"The siren, which the council says is "extremely annoying" for those who can hear it, relies on the effects of age-related hearing loss.
The authority said research had shown the Mosquito could be clearly heard by the under 20s, while those over 25 struggled to hear it at all.
Here's a sample:http://www.bbc.co.uk/wiltshire/audio/mosquito_sound.mp3
Can't hear anything other than traffic etc. Excellent! Where can I buy these? As long as they don't upset any of the neighborhood dogs...
Edit: Here's the sample played again, then slowed down by 20% so we can all hear it. http://yourlisten.com/channel/content/1 ... 4jzovs3l6o
Man, that would get really annoying!