I see its selectable in the menu  What does it do?

I saw a video explain you're supposed to be able to record audio, presumably through the tablet (?), to go with the video that you might be recording. Haven't tried it to know if it works though. I might also be wrong.

if you play, your videos in any TV with CC (micro sd adapter/usdb port) , the GPS and additional data will be displayed too.

Doesnt work for me. It's supposed to use your tablet or phone to record audio.

If it suppose to record audio From your iPad then I do not know because I was told that it records extra data to be displayed in playback on a TV. I'll try it and do a playback and see what I get, if the wind goes down. I have not been able to fly since the update due to high winds. I want to see about the audio.