Flying with a 4yo with special needs

I'm hoping some other parents or airline personnel might give us some advice on flying with a child with special needs. Our kid is four and has a chromosomal abnormality. She doesn't speak but is very vocal (and very loud). We need to start flying with her on a regular basis (a long cross country flight) and we are frankly terrified of the nightmare it might be. She's a happy kid, she won't be crying but she will be very loud and will most likely drive the other passengers nutty. Does anyone know if any airlines have parts of the plane that are noise dampening? Or does anyone have any advice for us? We'll of course bring her headphones, music, & videos. She doesn't eat, so we can't bribe her there. Any advice would be much appreciated! Chris

http://www.dotcr.ost.dot.gov/documents/acc/horizons.pdf

Since this is your child, I think you know what enviornment is the best for you and your child therefore bringing things to keep her occupied is a great way to start. Good Luck with your traveling....