Autism. Stop. Sssh. Think.
I would say it's a habit, but it's more than that. The way Bright Eyes operates when he wants something is to yell at the top of his voice, "Help" or, "I want dinner" or whatever it is that he thinks is necessary at the time.
It gets exceedingly annoying to be bellowed at from the middle of the house. No matter how many times I say, "Come and find me," he still does it. He just simply expects that everyone will drop whatever they are doing and attend to him immediately.
It gets worse when he's trying to build his railway set. He's not content with the rails to be on the floor any more, and wants to raise them, but he can't do it all the time, and gets loudly frustrated very often.
It looks like this:
And then frequently he goes back to the jutted out chin, raised voice grunting kind of bellow which he used to communicate with, exclusively, when he was three. That looks like this:
So today, I decided to go non-verbal and do a visual reminder of the steps to take if he wants someone's attention. I drew this up and stuck it on the wall. Hopefully it's going to work... I'll let you know!