Proactive is definately the way to go! You never know, some city people are THRILLED to have some country / natural sounds in their mornings. You may even say something like, "Hearing the chickens in the morning is like relaxing music to me, but I am concerned that they may be disturbing your peace."
If you have any indications such as the sounds of your chickens are directly followed by the starting of a lawn mower - on Sunday morning - then you may have cause for worry.
Are you sure you are not sharing any odors? I imagine that is of MUCH greater concern.
People are afraid of that about which they are ignorant. Fear breeds hatred. By all means, open up about your hobby, spark some interest and share some eggs (if you have them).