While I agree with those that say it is better to try and talk to the neighbor before involving the authorities, I also recognize that some people aren't as comfortable talking to their neighbors face-to-face (not a problem with me
)...and taking the chance of a confrontation.
A possible solution to that, might be to send them a letter anonymously.
You could nicely state something along the lines of...
"you may not be aware of it, but there are times when you and your guests voices carry a long distance and can be heard from several homes over." "We're not sure if your closer neighbors have complained, but we thought it was the friendly thing to do to make you aware of it."
While this may not fool the neighbors and they may still know that it came from you, there might be enough doubt that you can keep the peace when you see them in person.
Just a thought, before you have to take more formal actions.
