grunting/squealing instead of talking

DS does that sometimes, more often when tired. I think it's a bit different though as I wouldn't even say it lasts a whole day.
I stop, go down to his level, look directly into his face, tell him to count to ten (yeah, like he has a clue what that means), calm down and use his words.
I don't think he knows what I'm saying, but if I can manage to get eye contact out of him he generally re-sets and has another go at telling me what he wants.
Or I walk away. That sounds like I'm a bad mum, but sometimes walking away also makes him realise he needs to behave better to get a response, or he chucks a hissy for 5 min, then calms down and has usually forgotten what all the fus was about.