What you say for a parrots screeching sound?

i have a African grey parrot and he is 8 months old he screeches when i leave the room or walk away !!

what i do is i go back to the parrot and say ssshhhh it doesnt stop him forever but it trains him to not do it again

now my parrot is barely screeching mostly singing and barking

thanx for reading this and hope this helps you as it helped me