Seriously, just whisper and accept the stares. That's what I do. People lose interest in you after a while anyway.
The guy who's whispering to himself is fine. Weird, but at least not an asshole.
Second, yes, it totally does. The guy loudly talking into his phone is audible to everyone on the bus, thanks to the fact that he's speaking loudly. It's really obnoxious. e.g. http://www.youtube.com/watch?v=O0uTi2qkgf0
With that said, you could probably practice this stuff on the bus without being obnoxious by simply speaking more quietly. You'll still be more annoying than the quiet guy reading a book, but probably not unreasonably so.
It's a great conversation starter, too, which might land you a conversation partner if you're in a multicultural city.