God says, "Call to Me and I will answer you.." (Jer. 33:3). There will come a time when the people of God will no longer hear the word of the Lord (a famine of the Word as in Amos 8:11). God says, "When I called you did not answer, so when you call I will not answer [this is a warning]" (Zec 7:13). You, yourself have heard from God when you had that "Aha!" moment in the Scriptures and God made His divine impression on you.
I have much experience in the mental institutions and have heard it all. Heard about the shrink who told his patient that he was cured? "Well, what do you mean? When I cam here I was Abraham Lincoln, and now I'm nobody!" There are many crackpots who make all sorts of claims but it is easy to spot a phony--he doesn't have the credentials or credibility to back his claim, sort of like Elvis impersonators who are fooling no one. Many people claim to hear voices and some say others are just jealous because they don't hear them. Isn't it odd that certain drugs will cure them of this phenomenon? God is not the author of confusion and they are very confused individuals apparently. The mind is capable of playing tricks on you and make you think you hear something and sometimes it is a case of demon possession or oppression. Christians can be harassed by demons, though not possessed.
When you hear from God you are sure of it and have no doubt and can quote Him verbatim. You don't just say, "I think God is telling me to move to California, for instance." God speaks primarily through the Word. 1 Sam. 3:21 says, "The Lord revealed himself to Samuel in Shiloh by the word of the Lord." Ezra committed himself to study the Word of God (cf. Ezra 7:10). David, himself heard from the Lord on occasion, but that didn't keep him from relying on the Word and studying it and meditating on it. My pastor and others in my church have heard from God personally, but it is not new revelation per se, but something like 'I want you to put all your money in the offering as an act of faith" and so forth. God has not retired visions, dreams and directly speaking to us in this dispensation.
But before you accept someone's authority as having heard from the Lord make sure you test it according to Scripture and make sure it is in the Spirit. I do not blame skeptics that may call themselves cessationists, but they generally stay away from the Pentecostal and charismatic churches and are unfamiliar with the gifts of the Spirit--let them directly confront these Spirit-filled believers themselves before they judge. The gist is that God wants you to learn to depend on the Word and only after you do that can you expect to hear from God personally; he doesn't do it just to increase your faith or to make you better than someone else.