When you hear that voice in your head or heart, how can you tell if it's your own voice, the voice of God, or something else?
If it's your own voice, you'll probably say something that you agree with--like, "I'd sure like a piece of that pie." If it's God, He'll be telling you something you need to know--and it probably will have nothing to do with pie. If it's something else, it can be anything from something totally off the wall (eat ALL of the pie) to something that might even make sense, sorta (eat only the crust and leave the filling on the plate).
Another thing about the voice of God--He won't contradict the Bible. For instance, He won't tell you to move in with some guy (or gal, whichever) without the benefit of marriage. He won't tell you to lie, cheat, steal, or murder. (Murder is different than doing your duty as a soldier or defending your family or yourself, in case you were worrying.) You get the picture.
He gives comfort or direction (go there or do this), usually something you were needing or wondering about--but it can also come out of the blue. How do you know then if it's Him? He doesn't mind if you ask for confirmation. He might provide confirmation in your Bible reading, or a trusted friend might confirm it somehow, or circumstances could point to the same thing.
About 17 years ago, Go let me know He wanted me to move. I had bought a home in north Phoenix just a year before, and I really didn't want to move, but I had a hunch--and then He let me know. And then it was confirmed that week by my boss who brought word of an office in California that wanted folks with my experience.
If God wants you to do a thing, He will make sure you see the path you need to follow. It's up to you then to do what is required. You still have that choice, you know. He won't make puppets out of us.
Hearing the voice of God above the voices surrounding us is sometimes difficult, but never impossible. If you haven't heard from Him, maybe it's because you aren't listening?
God bless and keep you.