Does anyone watch Countdown with Keith Olberman?

[D_Roderick Beresford Stiffington IV]

Every now and then, especially during Oddball, he'll say a place, name or thing followed by "Hello!", in a voice I'm not sure what he's mocking. It sounds like Nixon, maybe Larry King, I have no idea but am curious. Maybe I'm just too young to know what that's a reference to. Can anyone tell me who the voice is supposed to be and why he says "Hello!"?

 

[D_Chaumbrelayne_Copprehead]

I think it's Larry King he's making fun of. I remember hearing him take calls, and say, in his gruff voice, "Tulsa, Hello!"