Although I'm using a GP8 for this video the same thing applies to the Osmo Action. The idea is to modify a mic that will stay outside the field of view for actioncams or any camera that uses a wide lens. Once I've worked out the simplest version of this mic I'll do a full build video and also use the Action to demonstrate the mic.
Lol the OA is not a wider angle lens so it does not really apply to it , but since you're offtopicing OA here is a a issue you have that can be helpful to you