I checked with my town prior to getting chickens and a permit was required. You are safer if you comply with the town laws to get your chickens even if your neighbors are totally for it.
Where I live (Framingham MA) the town sends a letter to the abutting neighbors to find out if they will be ok with chickens living nearby after you apply for a permit. They also did a site survey, to make sure we had enough room for chickens. If my neighbors had a problem with the suggestion of chickens they had to show up at the Board of Health meeting and state their objections. In our case, one of our 3 abutting neighbors did not want the chickens, but didn't bother to show up, so the board approved our permit. Those nasty neighbors called the Board of health this winter to complain about the chickens, and when the Officer came to inspect the location, he said they hadn't a valid complaint (loud clucking, really?!)
Anyway, I think if chickens are allowed in your location, but you need a permit, you are safer covering your butt by following the rules to the letter so no one has any reason to make a case against you.
Oh yeah, a funny after note: when the Board of Health guy came out to check out the neighbor's complaint, he asked me why my chickens had "bracelets" on their ankles. I told him that I'd had them inspected by the State Poultry inspector for avian flu and some other contagious disease to make sure no one would have any issues. He was amazed. He had no idea that the State Inspector checked out backyard chicken flocks. Guess you learn something new everyday.

Good luck getting your chickens, I know my life is better for having mine here.
Deb