When I was in school, all of my teachers referred to language listening exams (a tape is played, you have a sheet of questions to answer) as "aural" which mirrors calling the spoken exams "orals". Having not heard the word before, I could barely even tell the words apart when mentioned.
People don't say viva any more? For viva voce. I must be getting old.
Are all oral exams vivas? My (distant, secondhand) impression was that it was mostly used for the thesis defense.
Well the original topic was Heisenberg's doctoral defence. And yes, it is mostly use for that even though the term itself is quite general.