Piper doesn't say a word.
Shade does say some words, mostly in French.
"Shad-y-poo" (nickname for her)
"Peak-a-boo"
"Viens-t-en" (which roughly translate to "come here")
"Bisou" ("kiss")
You can see a video of her saying a few of these words
here. The quality isn't the greatest though.
Joey mumbles a lot.
I did, however, teach him to say "Hey Joey" when we come through the door. Each time I go come in the appartment, I great the birds, normally in the order in which I see them. For a while (before Petey and Zuri came to live here) this meant that he was last to get his greeting. Now I don't know if he learned to say "Hey Joey" pretty fast because if he says it before I have to a chance to greet the others, I have to respond to him first (I doubt that was why he did it, but I like to think it). She does also say "She-poo" when calling Shade...he's missing a syllable there
Petey is my biggest speaker. However, I heard most of her vocabulary when she first came here and was still nervous. Once she got comfortable, it kinda stopped, all but "Hey Petey" when we come through the door (it's a competition between her and Joey who can greet the faster; kinda funny).
Zuri doesn't say any clear words, but I have heard her mumble under her breath when she thinks we aren't around.