Hearing voices doesnt need mean that you are crazy. Once they start doing demented things to you, thats bad.
At times, I catch my sub conscious thinking. Its the neatest thing. I became aware of it because I have practiced for years at persisting in a state partway between awake and asleep. It seems to mull over little fantasies until it gets something it likes, then it blasts me with it, and I get the usual day dreaming experience.
This is during regular conscious times, btw.
The reason that I catch it is because it kind of thinks something quietly, and a few seconds later I hear a louder "echo thought". Because of my practices, sub conscious thought sometimes imprints in short term memory, and it persists long enough for me to remember when the full blown thought happens.
To tell you the truth, I think this is what "deja vu" is. An echoed thought.
Currently I am struggling to attach sub conscious thoughts to longer term memory. There seems to be an internal consistancy to subconscious thought as well as rules. The problem is remembering the experience properly, so I can articulate them better.
Off hand, I can say that our minds do less creating that we think. While we dream, we think that our minds are filling form and action into all elements in the dream, but most things are static, they dont move. Unfortunately, in a dream, if you focus on an element, the mind fills out its details. It is only through detached attention that I have noticed this.
There are a couple of other general 'rules' but I dont know enough about them to say for sure if they are common to all people, to autists(because I am one), or just specifically to me.
Oh, and as far as tinnitus goes, it can sound like music or harmonic singing too. I get it too, but its ususually just a buzz or ringing sound.