Yes, other people do hear Noah's mumbling conversations with Ciel.
And no, they do not like them.
So great ! In other words, that's your problem man, get over it.
completely understandable for *insert name of character i forget XD* to freak out at Noah :P
Will Ciel understand, if Noah doesn't say it aloud and only moves his lips?
As a fellow thinking-out-loud-er who is also prone to vocalizing the special effects going on within my head, I feel Noah's pain.
Pew, pew, pew, pew! Brrzt! KRRKOOOMM!! Frwoosh! *crackle, crackle* Hahah!
This sceptical look as if Noah should be happy about being told something like that XD