About cell phones not so long ago, most casinos banned cell-phone conversation at poker tables. But now that everyone has a cell phone and with casinos aware they can't make money with players away from tables cellular conversations are usually permitted as long as they don't interrupt play.
Live poker is intrinsically a social game. It's "a people game played with cards," as the saying goes. As such, conversation is part of the game. Poker would be a boring, miserable experience if it had to be played in silence.