Well, i guess things that others don't understand will get you bullied. I think hearing voices is really a defect, I'd say on average it has a negative effect. They know nothing you don't, they are pieces of your mind. I don't think there's a reason to embrace it or to throw it away. If you accept that it's a part of you, then you can deal with it. Sometimes they'll give creative ideas or suggestions, sometimes they'll drive you mad. Never forget what they are. Probably best not to tell people you have it, even those you trust (as your relationship might weaken over time) if you really wanna prevent getting bullied for it.
Maybe you can present it as something other than "hearing voices". Say that your alter ego sometimes gives you nice ideas,or that sometimes you "just get cool ideas". When it's rather negative, say that it has to do with a rough past or something.
Never talk out loud if you do feel the need to talk to them. They can hear your thoughts, so no reason to speak. And maybe you can slowly think of them as part of you, and not some separate thing. You can try going to a doctor for some quick advice, otherwise i recommend not letting it be too important in your life.
They are just a part of you. Parts, not wholes, not separate things. Different ideas of yourself.
Good luck with that