I'm sorry, this may be a bit long. Trying to help my teacher out.
My accordion teacher recently replaced her TV downstairs with a new model. She does a lot of Skype lessons (including with me now that I'm not in the area anymore), and has been using her iPhone 7 for them, hooked up to some computer speakers. Now that the old flat-screen +/-40" TV is free, she has moved it upstairs to her lesson space, and bought an adapter to output her iPhone's screen to the TV, so she can see the students a lot better during lessons. However, now the internal mic no longer suffices for her end as the iPhone is a ways away for both video placement and being restricted by the adapter. The mic doesn't pick up much any more. So, what she is looking for is to be able to have the iPhone's screen on the TV but also to have an external mic for better sound quality.
On my end I use an iMac with a thunderbolt interface and a condenser mic during lessons, which sounds great, and I'm wondering if there isn't a way to do something similar on iOS. I know there are interfaces that can be used with iOS, and also that Skype only sees one input and runs in mono. That's fine in this case. What I'm wondering is if anyone has any suggestions for being able to have an external mic, while also transmitting the screen to the tv for lessons.
Looking around the internet, it looks like a possibility may be to buy the USB3 Lightning camera adapter, connect a USB hub, then connect an interface to that with a mic. That takes care of the audio. What I am wondering then, is since there are usb to HDMI and USB to VGA adapters out there for computers, if they would work with the hub with the iPhone, letting the interface, mic, and video out all work with the iPhone 7?