Whose voice is that inner voice?

I will hear my mother's voice at times making a running negative commentary say for instance when I look at myself in the mirror it is her voice in my head criticising me. I've told various mental healthcare givers this and none have really reacted to it so I figure it is fairly normal. Now if you were to be having a conversation with the inner voice or it was telling you to do some inappropriate behaviour, that might be concerning. Anyway, what I am trying to say is I think it normal to an extent to have an inner voice - call it perhaps your conscience.