Or, you know, everyone's bodies are different and he just happens to sneeze differently from you. When I sneeze people think it's a cough.
I've just realized something: my dad, mom, sisters, and brother are loud sneezers, though I have to give them credit for at least trying to cover their mouths whenever possible. I can always tell when I feel a sneeze coming, so I always reach for my pocket hanky like a gunslinging desperado. Sometimes I even try to "delay" the sneeze by pinching my nose and closing my mouth while reaching for the Kleenex. When I'm alone in my room, I don't bother so much. But when I'm out in public or at work, I'm a lot more cautious.
We all do, however, have control over our lungs and bodies, and we all have control over how we sneeze to some degree. If I wanted to I could make my sneezes sound like a tie-fighter screaming down the aisles, but I know it would be bothersome to people so I don't.
I'm wondering how my youngest (and he's a Kindergartener, thanks) will sneeze when he gets older. Right now, his sneezes are an EVENT, truly awesome to behold! He has a loud, long, several second build up, then the explosion: aaaaaAAAAAAAA-CHOOOOOOO! And my wife thought my sneezes were impressive! (They are, I just usually have 8 or 10 in quick succession.) We really don't think he's artificially building them up, either. As for etiquette, I try to sneeze into my elbow, or at least away from everyone when I can't get to my elbow. Not sure when I started doing that, but I'm pretty sure it was within the last 15 years, which is after college for me. I really don't remember anyone doing anything but using their hands before that. I think some sort of cultural/health shift happened with that pretty recently.
If i'm alone outside I just sneeze to my right. I always walk with my right side towards the.. ditch? When i'm with other people outside or inside, or when i'm inside at all, I cover my face.