What can I do about noisy neighbors?

I would go over there and ask them politely to keep it quiet at night because you are losing sleep. If it doesn't improve write them a certified letter stating that you have asked them to keep it quiet and if they don't do so you will be forced to involve the local authorities. You could also talk to other neighbors to see if they are having the same issues and include their input and signatures on the letter. Hope it all works out for you!