Most of what I have seen regarding this subject is that your personal character and conformity to Christ will determine what you 'hear." Therefore it is risky to establish a doctrine of mystically 'hearing' God apart from maturity in the Word and in conduct.
That God 'speakes' to us is certain. For example there is this verse from James...
"If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him.
Yet character is the filter by which we can hear God. For instance, what would a fool do with wisdom? Fools always want wisdom at the 11th hour, but would a fool even recognize wisdom if it was given?
In my experience, a person who can 'hear' wisdom is not a fool in the first place. (At least not an arrogant one ;-) )
If we get too confident of our ability to 'hear' God without the Word, we might associate our own inclinations with 'God's voice." (This is why Godly inclinations are a prerequisite for hearing Godly words.) For example an ex pastor of mine seemed to blur the lines between his own disposition and God's moods...when he was feeling melancholy the "spirit' must be feeling melancholy, and when he was in a jovial mood, the 'spirit' must be wanting to celebrate. Almost every Sunday, he would interupt the flow of worship services to tell the people that God wanted slower music now, or faster music...or he wanted testimonies. During the sermon he would veer off topic for a second and then explain his digression with a casual comment "Someone in here must have needed to hear that." (Implying that every word he uttered was spirit-led...)
Likewise, I can remember in times of personal distress I would pray with such sincerity untill I became convinced I had 'heard' from God. Indeed, sometimes these things would bear out and other times I wonder if I was hearing simply what I wanted to hear...looking back much of my prayers in those circumstances were immature...I was facing the wrong direction spiritually and yet I was 'hearing' the Lord and other people were 'hearing' the Lord for me as well.
The things we were 'hearing' are a GPS marker indicating how misguided, a passionate sincere Christian can be. The words we hear often indicate our sincere longings, fears, and beliefs.
Another example...once after a particular time of spiritual renewal a friend came to me sharing that the Lord had impressed upon him that I had fallen away. It actually pained me to tell him he was wrong...I didn't want to embarrass him. Yet he was often prone to give me words like this because he had assigned himself some role of a mentor in my life...and he couldn't accept growth in me. The 'word' he heard was just a reflection of his own beliefs about me.
Examples like this show me that the first order of business is not 'hearing' from God but applyng what we know to do from his Word and let Christ be transformed in us. Once we are more Christlike, our sense of 'hearing' will become more Christlike. So will our other senses and spiritual giftings. Even spiritual gifts are not safe in a person who is void of Godly character.
There is much interest these days in the experiences of a mystical union with Christ, such as hearing God inwardly. I readily admit my own personal journey has often taken me into this area of interest. However I am careful to not lean too much on these experiences...but regard them with healthy suspicion.
Not that I am suspicious of God's desire or ability to speak to me, but suspicious of me, a corrupt vessel, and my desire and ability to hear.
As someone wanting balance in this area, I admire the Whitefields, Edwards, and Wesley's. They were evangelicals precisely because they preached a living vital connection to Christ, but they always emphasized Christ-like character as the manifestation of this connection more then mystical abilities.
MC