Hearing voices...

Well, your question seems to bring up more questions than answers.  I would tell you to please speak with a licensed therapist in person to discuss what is really going on for you. People often relate to "voices" in their heads that are thoughts they have that came from other people in their lives (ie: mothers, fathers, teachers, ministers, etc...) Some people "hear" voices that are not related to their past or to their beliefs, etc Both situations need to be addressed so that you can have a better understanding of what all this means and how it impacts (or could impact) your life.

I am glad to hear that this does not really bother you, but since you sought out information about your situation, then it is taking up space and time in your day, and therefore I believe it should be addressed. I would recommend that you seek out a psychotherapist who can evaluate with you what is going on and insure you are taking the best possible care of yourself.

Voices in your head don't always have to be telling you to do terrible things, but when they cause unnecessary distractions from everyday living then the issue needs to be addressed appropriately.  If, as you say, you have been aware of them forever, I wonder if you have told anyone about this, and I wonder how it impacts your life.  Like I stated, I would recommend that you speak with a psychotherapist (Licensed Clinical social Worker, PhD, or MD) who can most accurately assess what is happening. I strongly suggest that you get a recommendation from someone you trust, (perhaps your family doctor).