  This paper explores how ambiguity affects communication. We consider a cheap
talk model in which the receiver evaluates the sender's message with respect to
its worst-case expected payoff generated by multiplier preferences. We
characterize the receiver's optimal strategy and show that the receiver's
posterior action is consistent with his ex-ante action. We find that in some
situations, ambiguity improves communication by shifting the receiver's optimal
action upwards, and these situations are not rare.
