My b&g macaw Sami had several distinctive 'hellos' -- one was a very soft drawn out and flirtatious 'hel loooooo' ala Joey on Friends. I had her whole life, so no idea where she learned it. For real. I don't say hello like that or know anyone who does. But she does have my own telephone pick-up voice 'hello' down pat. Would often say hello as soon as the phone started ringing. lol
(Just so you know, after 20 years of keeping her, I purchased a spot for Sami at the Cape Fear Parrot Sanctuary -- so she's free-flying these days with lots of macaw friends. My favourite days are when I visit her there. She suddenly ditches her new flock and plays the baby macaw role for me for old times sake -- adorable). This is the same sanctuary where my CAG will go when I die. I kept him because he isn't socialized (had him 22 years) and he pretty much only likes me, afraid of new situations, etc.. Whereas Sami never met a stranger and considers everything an adventure. I wish my CAG Snickers was more outgoing with other people and parrots).
[Sad to mention: many greys don't 'make it' at the sanctuary and the various owners/sanctuary supporters end up giving them indoor homes. That said, about a dozen+ greys did adjust well at the sanctuary and are free to fly and flock! My dream is my Snickers one day adjusting to such freedom -- fitting in with the flock and flying free!]
Also, wanted to add that giving my better-adjusted happy parrots (b&g macaw, YN amazon and 22 yo cockatiel -- companions for 20+ years!) having their freedom back was the HARDEST choice I ever made. I decided their happiness meant more than mine. An incredibly difficult choice, nonetheless. They're happier than I am with the choice. I miss them... then I remember them flying and preening each other.... well, they're happy in a flock flying.... At least I can visit whenever I want, and I do, often. Parrots NEVER forget you.
I write this extra bit about a sanctuary because none of us live forever, and planning for your parrot's future is incredibly important. Parrots are rehomed at an alarming rate and making plans for mine as I get older was important to me. And to you. Because we love them so much.