Hardness of Heart in Biblical Literature

Every speaker, teacher, or preacher has on some occasion encountered an audience that was unreceptive to what he or she had to say. One response to such communication breakdowns given by both the Old Testament prophets and New Testament authors was to declare that the hearers "have hardened their hearts to the message" or that "God has hardened them." What is this hardness-of-heart phenomenon? Who became hardened and why? Was it a result of some "deficiency" in communication? What were the conse