This is a harder question for me. I have Other me and I'm not sure if she counts as a voice or not, but she's inside my head. She's not a mean voice, though, if that's what she is. We were just talking this morning because I put on my favorite radio talk show on the way to work and I could hear a background talking. So I asked her if she thought maybe someone was trying to listen in on me? She said it could just be the radio station didn't connect all the way, push the button again. So I tried and it stopped. See, she helps me with things like that sometimes.
I do hear outside voices/sounds, but not often.