So I know I am not supposed to stick the Q-Tip all the way in my ear - so sue me. Anyway, when I do this in one ear to clean it out, that’s all that happens - I clean it out. When I stick a Q-Tip (not the same as the one I used in the first ear, thankyouverymuch) in the second ear and clean, I cough.
How come? I mean, I assume I have tickled my eustachian tube in the one ear which translates to cough. Why doesn’t this happen in the other one?
The reason whe one ear makes you cough is easy enough - the nerves in that area are multiplexed to some degree, using the same pathways to carry different signals. It’s called a “referred sensation” (or sometimes “eccentric projection”), and the one you describe is a commonly-used example.
Presumably this is a form of efficiency on the part of the nervous system, as the need to tell the two sensations apart was not high enough priority to develop completely distict pathways.
Why the *other * one doesn’t do it is less clear.