Hey, the talkback mic is a great idea. To do this you will have to use an external mic plugged into your 6i6. The reason is that iOS has never allowed “aggregate audio input” meaning, as soon as you plug in the 6i6 it takes over all inputs/outputs on the iOS device. The iPad mic is always disabled when an external audio interface is plugged in. Jonatan might have additional info, but I’m fairly certain this is not an AUM problem, but a limitation of iOS.