Screaming Parot

Question
I have an orange tipped amazon (31 years old, had her for 30 years).  Just recently she started SCREAMING.  She use to be controlable, but lately she is uncontrolable, unless her cage is covered or she has a piece of food in her mouth.  She is not lacking anything.  When I tell her "No Scream," she stoppes and then in a matter of seconds starts again.  She understand EVERY word I say and she knows she will get hollored at again for doing it.  She does it really mean.

Answer
First, I would take her to the vet just to make sure she's not screaming for a reason. Don't cover her cage when she screams or she'll just scream even more. Instead of saying "No Scream" when she yells, turn around (don't talk, or even look at her), turn the lights off, leave the room and shut the door (if you have one). Come back to the room only when she's been completely silent for 8 minutes (weird time amount, I know, but it works the best with amazons, I've found) and then give her LOTS of attention and treats. Do this EVERY time she screams and the screaming will be gone in a week or so. This method has never failed me.