To hear and listen, not "go in one ear, come out the other ear".

If that is its direction of flight, yes.

Yes, she has 12 piercings in total. 4 on her right ear and 8 on her left ear.

Not sure which one, but the difference between an Asian elephant and an Indian elephant is the ear. One has a smaller ear and the other has a much larger ear.

It sounds like you might not have a problem with that ear, but rather the other one. It could be that the ear without wax hears normally, while the other side may be muffled from compacted ear wax. If you have not had a professional look in your ears with an otoscope, you probably should.