Rocky was an attention hog last night. He could not get enough of us! Repeating "hello!" is one of his ways of begging.
In this video, he climbed from his cage to Stella's and then kept saying "hello!" to me while wandering around her cage. I answer him back -- but you should be able to tell what is me and what is the parrot.
He may also have been begging a bit because his routine of late had been to go inside Stella's cage and eat her seed while she was in the kitchen. I closed her door last night so this wouldn't happen -- he has his own seed!