Well, Jesus appeared to his diciples after his resurection. I think that's about the only example of that (written down) that I can think of in the Bible. I think that Paul and John, probably a couple of others heard his voice too in NT times.
I know that I've had personal revelation through the Holy Ghost many times. But that is different that hearing God's voice.
I don't agree that we don't need direct revelation from God. If anything, we need it more. Satan has been succefull in making the world a pretty evil place. Jesus will be returning soon, so we need to be ready. Of course I beleive that God still uses Prophets today as well. I've done a lot of soul searching with religion, and I don' t think that God gave us a Bible then left us to fend for ourselves, with no prophets, no miracles, and no revelation to help us. Why would God do that to the ones he loves? To borrow from Black Wolfs analogy, would you do that to your children? Or would you give them everything they needed for success? We're not teenagers or young adults, we are mere babes, lambs. Mankind now beleives ourselves to have superior knowledge and we can explain all things. Mankind, in general, beleives more in science (the way God made things), than God (who made all things). In a way we are worse off than the Old Testement people, spiritually, because they looked more to the Heavens than they did their own hands. I do agree that the spirits inhabiting the earth now are stronger than the generation that preceded them. God is sending out the most valiant, because he needs their strength to combat the great evil that has risen in the world. The strong spirits that hold fast to God will perserve us in the last days. But it's through modern day revelation and guidence that the strong remain strong and not become corrupted by the carnal.