I know they are neighbors and you have to try to appease them but seriously how long can they possibly be barking when playing with each other? Sometimes you just have to tolerate a little barking! If it goes on solidly for hours at a time, I could see the issue but I am sure it does'nt so I wish you luck because your neighbors sound like grumps! I hope that you dont put a collar on them that inhibits their " making joyful noise" when playing with each other!!!