Okay, I think I am answering my own question. I was reading about the RAC and not the RSA. I did find the part about the RSA (and I have it), so it looks like we can do that. Does anyone know if earphones are universal in size?
I have had people in the back listening to the DVD on the screen through the headphones while I listened to the baseball game on XM. They control the volume with the headphones themselves and yes the headphones are universal. I have had full grown men with big heads wearing them and 3 year old kids wearing the same headphones.