I do but thats normally singing stupid songs.
My friend and I do that a lot. He does it more so. Its called monolog.
I think you have problems.
While I play games..
I sometimes talk to myself in weird voices, and when I do talk to myself it's usually to think things through. But I will also yell out things like "Damn girl yo ass lookin' fine tonight!" while looking at myself in the mirror just because I can.