Just a thought from the posts so far.
Here are some results from Google.
Wireless Mics
Coupled with the screen recording from the on board recorder of iOS products as suggested by
dirkclod
In iOS 11 or later, you can create a screen recording and capture sound.
support.apple.com
And
SmilingOgre suggested the use of a clapper board.
When I flew with my Mini4 and the Spark a while back, this iOS clapper app is cool and used it quite a few times.
It makes organizing the flights easier with a thumbnail frame of the clapper board.
DigiSlate is a modern, free digital slate / clapperboard for iPad, iPhone and iPod Touch. DigiSlate uses either a swipe across the board or the volume buttons on your device to clap the board. This allows you to keep your hands well out of the way when the slate claps. DigiSlate uses the...
apps.apple.com
There's bound to be a solution to your situation, just have to figure it out.
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