Eli5: Why do we say “achoo” when we sneeze?



Eli5: Why do we say “achoo” when we sneeze?

In: Biology

Really the functional part of the sneeze is the “Tch” part. The point of a sneeze is to try and dislodge an irritating foreign substance from somewhere in our respiratory tract, and the way we do that, is to build up pressure in our lungs, and pinch that pressure off by pinching our glottis and mouth shut, and then suddenly release it. That explosive burst of air coming through our mouth and breaking the seal between our tongue and palate, is what produces that distinctive “Tch” sound.

Some people, when they sneeze, you really only hear the “tch”. When they first build the pressure up in their lungs and release it, they just aren’t letting their vocal cords vibrate with the passing air, so you don’t hear much “voice” along with it. For other people, it feels more natural to let that rush of air excite their vocal cords too. Hence the “Ah” and “Oo.”

Do you mean why do we say “achoo” specifically or why do we say anything at all?

The reason why we sneeze most of the time is because we have something in your nose that’s not supposed to be there, and the sudden air flow is meant to remove it.

The “achoo” part is cultural, like “ouch” is when you are hurt. In different cultures people make different sounds when they sneeze. It might be hard to imagine, “achoo” just sounds so natural. It’s what you’ve heard your parents and your peers say when they sneeze, and it’s what you say.

But in another country and another language people might say the same thing about “haptsee”.

Saying something when you sneeze is a learnt behaviour – we only say “achoo” because we have heard everyone around us do it

In other countries, different sounds are made when people sneeze. For example, in Japan people say “hakashun!”

Deaf people, especially those born deaf, do not say anything like this when they sneeze, because they have not been conditioned to do so