Constant Barking.......Please advise?

My neighbor has two large dogs. (not sure of the breed. nothing I could name off hand.) They are often allowed to be left out in their backyard during the daytime hours. They are well treated and not underfed and are always left with adequate water. HOWEVER, if so much as a squirrel passes through their yard or a car goes by in the street they both start barking. The barking can go on LITERALLY for an hour and a half without pause. I work from home and find this EXTREMELY disturbing. I have already spoken to my neighbors multiple times and while they are apologetic and sometimes attempt to quiet the dogs they are simply not able to. I have even called Code Enforcement to get further options and gotten no help. Does anyone have any advice please! They've been barking just now for 45 minutes straight and I can't stand it!