With short turn around times, aircraft maintenance personnel have to work quickly and efficiently. No airline wants to find that passengers cannot access audio on their IFE system, so broken audio jacks have to be identified and fixed.
The clever design of the jack is that the LED is powered by the audio, making this a fantastic jack for retrofit as no extra power is needed. All the maintenance staff have to do is send a high frequency audio tone through the existing IFE system, then walk through the cabin and check the jacks at a glance.