When I leave Hemingway for any long periods I roll his cage in front of the TV and put on cartoons for the day. I know the sounds and action keeps him happy, because I have video taped him many times to see what he is up to. It’s funny when an animal makes loud sounds, how he gets involved. Try it, and you will know your bird very well. 10 hours is not that bad but yell and scream with joy and give him his favorite snack as SOON as you get home. Plenty of snacks, HAND feed him. He won’t be mad at you.
Good luck
Joe