I have seen a number of in flight entertainment systems which utilise two 3.5mm jacks for their earphone jacks, instead of the 1 jack with 2 channels normally used in almost all applications.
An example (from Singapore Airlines) is shown below.
A normal 3.5mm 2-channel jack is shown below as contrast:
Why is this done only in airplanes (to the best of my knowledge)? Is there a reason behind this separation of audio channels?
