You know when people do the Yoda voice, and their voice breaks because they can't keep it up? Is there a name for that?
Back in 2000 the brilliant Nintendo 64 game "Perfect Dark" shamelessly imitated Yoda's voice for one of it's key alien characters. The Yoda style voice however, can be heard to fail on a few occasions during the games cut-scenes.
Can you even be said to be doing an impression of Yoda? For instance, If I do an impression of the primeminister, I'm doing an impression of a real person (unfortunately) he is the real one, I'm the fake. But Yoda isn't real, he's voiced by actor Frank Oz in the movies and Tom Kane in the games.
He is a puppet in the old movies and CGI in the games and newer movies. I wonder if Frank Oz hates Tom Kane? I mean, who is Tom Kane? Anyway, is your version of Yoda any less real than Frank's or Tom's (There is a Peter as well, but forget him)
Does the fact that these guys are contracted to do the Yoda voice mean they are the "real" voices of Yoda. What if 10 people were employed to do the voice? Are they all the real voice too?