I just wanted to mention something, with all due respects to the suggestions zuzzozz gave to talk back to these voices, my personal advice, and that may just be my preferential point of view, DO NOT speak back to these voices, especially in your head. The reason for that is that I have experimented with this and the truth is it may make one psychotic and make one go into a delusional tantrum, especially if the voices keep at it.
Think about it, when someone meditates, that person is attempting to get into a tranquil state and find inner peace. Do something like scream back, inside your head, to these voices, and it will have the opposite effect that meditation should have.
So please, if anyone else reads this, DO NOT attempt to speak back to these voices inside your head, instead try meditating, but please no one assume a real voice is speaking, the voices that I hear are too mechanical and repetitive like a mantra, they are not real, trust me, it's something else.