It is possible it could get worse. This sort of the thing is more likely to start happening in a person's 20s. I would say it's not normal.

I started hearing voices in my 20s. Most of them sounded like myself thinking, like as if I would think a thought to myself in words, only I was hearing voices doing this on their own. A few of them sounded external, like I was hearing something else outside myself. It was not too intense and it came and went over a period of months until stopping. When I was in my teens, sometimes when trying to sleep I would hear faint chatter as if a TV was on in the house.