Your brain stores the sounds of voices, doesn't it?
Sometimes when you're expecting to hear something, you hear it.
Like with cell phones.
The cell phone went off two times in a row, after that I kept hearing it. But nope, no new calls. No missed calls.
It was just in my mind.
It's like sitting really still and focusing, sometimes I feel like the Earth is rotating under me, I think it may just be because that's what I know and expect to feel.

For the voices, it could be a stored sound memory of your parents fighting or something, and it's just playing in your mind.
Just remember it's probably not real, and listen to some music or something to get your mind off it. There's no point in stressing yourself out over something like that, is there?

And you're NOT crazy. I bet everyone experiences something like this at least once in their lifetime.

Well, I hope that helps.