God speaks through signs, through thoughts, through images. I've never heard God vocally. If it's God speaking to you it may be like there is a thought popping up in your mind, and you know it wasn't from your own self. Often it's some verse from the Bible as an answer to a prayer or situation you are in. Here comes the important part, to learn to differentiate what is from God and what isn't.
For me, this is most often.
I have a couple of times received dreams that were immediately followed by "a thought popping up in your mind, and you know it wasn't from your own self" that identified the Lord's purpose for the dream.
There have been two times--within hours of each other--that I have heard what my brain interpreted as a physical voice. In both cases, the voices appeared to come from just behind my right ear. But by the nature of what they said, I know they were other spiritual beings, not the Lord Himself.
But those voices were not the Lord. This was a time of immense personal stress for me, on my knees in prayer in a dinky motel room with a court date for the next day for a case that my own lawyer told me I would lose. Little did I know in a moment of near complete despair that God was about to do something big in my life.
The first voice said to me, "God didn't help you before, and He's not going to help you now."
It referenced an earlier situation that I immediately recognized. Minutes later, something happened to confirm what that voice said--a pit that had already been dug in my path and waiting for me.
But also waiting for me just beyond that was a fellow believer who told me the right thing at the right moment. I had been fighting the battle myself for months, and I had told God where I wanted Him to come in to my plan.
I got back into that motel room, back on my knees, and I gave the matter to the Lord, ending with the words, "Whatever you choose to do tomorrow, Lord, I will always praise your name."
That's a witness for a different thread, but some things happened in the next hour--a battle of spirits right there in the room, darkness replaced by light.
And when it was over, I was standing on my feet in wonder and said to myself, "Now what?"
That was when I heard the second voice, a different voice also behind my right ear, say, "You finally said what we waited to hear.
Just be there. And watch."
I praised God that night. I got up praising God all the way to the courthouse.
I took my seat in the courtroom beside my lawyer with the six-inch-thick brief that I'd spent thousands of dollars compiling.
The judge--a judge I had long known was opposed to me, my own lawyer had sussed that out and told me--walked into the courtroom. He didn't even sit down. He said, "I want to see both counsels in my chambers."
Twenty minutes later, they walked out. My lawyer looked at me and said, "We won."
They hadn't even taken our brief into the judge's chambers.
It was completed at the last minute, but it had been laid in place months earlier. The state Supreme Court had just released a verdict on another case that invalidated the case that had been drawn against me. The judge's hands had been tied by the Supreme Court ruling.