Talk show micing...what's the deal

I’m sitting here watching Conan O’Brien talk about how he’s surrounded by mics. He has a mic attached to his shirt, and a big mic sitting on his desk, as well as mics floating right above them. The guests on his show always have mic’s on their shirt as well. Any of you audio technicion dopers know why these talk shows need so many mics if they’re only used for speaking?

The mic on the desk is just for show. And the lapel mics are clearly to pick up vocals. As for the overhead mics, I would guess that they are there to pick up some of the environmental noise (i.e. shuffling papers around), as it would probably be a little weird for thier voices to be the ONLY sound coming out of your TV. There are probably even more mics that you can’t see (such as the ones to pick up the audience noises).

Hmm, I figured the big desk mic may only be for show, but I’ve seen Conan knock it over and bang it on his desk so many times that it is obviously active. Maybe it works like you suggest the overhead mics work, that it’s mainly there for picking up non-vocal noise?