Today I tested the microphone, reason is I will make videos when I'm on the road, talking. I will not publish a heap of videos with just road, I can't myself stand watching endless filmed roads for very long, I need to hear if there's a story.
I found a couple of holes in my inner part of the helmet, perfect sized for the small microphone capsule, that I once rescued from a professional wireless microphone system, when the frequencies became illegal. The sound is very high quality, but I was uncertain if the wind and turbulence ruins everything. I was wrong, audio works very well.
I'm using a GoPro 9 Black with a Mod and a GoPro Max. I bought an GoPro-app, but I don't think it will be usable, the buttons are way to small. I will either buy The Remote for GoPro, or a bundle with another 9 and spare batteries.