Just a thought, I had a friend who was old southern friendly type, moved into a new condo neighborhood in a new city. She baked a pie for her next door hooked on neighbors. They accepted the pie when she knocked and introduced herself and presented them with it, looked at it like it was about to explode, and later, she watched them as they carried it out and put it in the trash. In today's world, I'm not sure if I would be willing to accept a food item from an unknown stranger who's just moved next door either. She later got to know them a little better and they turned out to be very strict vegans, very strange folks anyway.
As someone who has worked with and even raised some neurodiverse children in my time, I think all these suggestions above about how the family below can cope without out and out demanding, unreasonably, that the unstairs children conform to their noise requirements are excellent.