Kudos to you for trying to be cooperative. Sounds like they tried to "hold their tongue" for a whole year, hoping the chickens were a passing fad, so they have tried to accommodate you. About 10-15% of people are highly sensitive to noise, and random loud noise can detract from enjoyment of their yard, ability to entertain, ability to read or concentrate, napping during day, etc. I'd try to get as much detail as possible about what/when the noise is disturbing and attempt to mitigate. I'd move the coop if it is logistically reasonable, try to insulate for sound, and perhaps turn chooks out later in the day if noise is in a.m. Try giving flakes of leafy alfalfa hay to keep them busy and entertained. As someone who lives next to new intrusive mechanical noise exponentially louder than chickens, I can say it's profoundly distressing to not have the peaceful use of your outdoor property. Regardless of ordinances, one can be subject to a nuisance lawsuit, maybe impossible to prove but still unpleasant.