Ok, now it makes sense. Usually, they suggest to divide the whole thing in single elements (except for who starts working on something from zero), so the result won't be messed up, but in this case you have only one track: the fact is that having the vocal on the same track as the background, you can't slow down the vocal without the rest and that's why I hear shots... it's not that I imagine things, but try to slow it down and you will hear the difference yourself. It's like the background goes against the vocal because it's too fast. I wonder if you will be able to understand since it's really difficult to explain something so abstract. Which software do you use?