For the screaming I think a lot of kids (and sometimes adults) with disabilities truly don’t realize how loud they are. They feel strongly and their volume reflects that. C is like this and at 15, I will just say “Do you realize you are screaming/shouting at me?”. And he will try again lower but still not quite a normal volume but he catches it and hits a normal volume on the third try usually. [emoji2356] And yes, he’s totally acutely aware of any whisper of irritation in my voice and feels yelled at then even though I’m not raising my voice at all.
It took years to get to this point but I think the breakthrough was when I told him when you are yelling, it stresses me out and my brain can’t even process what you are saying or understand what you need.
When he was little and shrieked a lot, I would cover my ears and loudly say “Ow, that hurts my ears!”. I found it necessary to be a little more dramatic than I normally would. Yours are probably way too old for that.