Why do we say "achoo" when we sneeze?

Who knows what the winds gonna bring when the invalids sing?

Note that guinea pigs only have small vocal folds, but still sneeze (it sounds like “chuh!” rather than “achoo!”.

I wonder what the sneeze onamatopoeia is in other languages?

Take a look at the wikipedia table in post 12. Interesting stuff!

Because people want there to be. You can have a loud showy scream when you sneeze and annoy people, or you can sneeze without adding any vocalization at all.

I agree with you on this, but in at least one past thread there were people offended at the notion that they could avoid loud screamy sneezes if they wanted to.

As far as other languages - I had a colleague from Pakistan who always sneezed “Heshu!”.

I think it is just a habit they are not interested in trying to break (not saying they need to either).

There is no physiological reason to vocalize when you sneeze. But if you do…ok.

The vocal cords being involved wouldn’t necessarily mean that it would sound voiced. You constrict your vocal cords when you whisper, for instance. This is why you are told not to whisper when you’re taking a vocal rest after a vocal injury.

I was actually somehow able to make myself sneeze just now, and what I heard sounded like there was a very brief amount of vocalization while breathing in. But the actual sneeze part–the expulsion—seemed unvoiced, only making sound through my teeth, like I was doing a Donald Duck impression.

And my DD impression, at least has never involved my vocal cords. It’s high pressure air through my teeth, to make a quacking-type sound.