Originally Posted by
Firemansam
Standard 2 pin adaptor will be absolutely fine. The 3rd pin is generally to supply power to the airline's noise cancelling headphones.
I can tell you positively that it won't work fine. It didn't on my recent round trip flight (different Airbus) on China Airlines using the standard 3.5 mm to two prong Bose adapter. I also tried a backup AliExpress adapter, different seats and the cheap in-ear 2 prong headphones which are given to economy class. Only an actual 3 prong 3.5 mm adapter works but it seems it's proprietary.