Older thread, don't know if you'll see this, but I'll answer anyway. We didn't change Scooter's name, exactly, but she's now learned a new adjective.
When she first got here, she'd say "Scooter! No! Quiet down!" I guess she heard that a lot. Now she whispers to herself "The good Scooter. I love Scootie." She's decided her name is now "good Scooter".
They're incredibly adaptive, under the right circumstances. I knew a guy at UCSB that studied them in the wild, and he told me when parrots join a new flock they have to learn that new flock's calls and sounds. Scooter was fascinated by the sound of whispering, so we whispered to her when she first got here, and we always tell her she's a good Scooter, the best Scooter ever. She adapted to her new flock's whispering, and that's what she does now. Mostly. We also gave her a bell, and she uses that to summon the staff (us).