BACKGROUND: My daughter has purchased a GoPro Hero5 Black and in order to eliminate engine noise wants to use it with aircraft headset com/intercom audio rather than the internal microphone. The idea is to tap into her headset's receive audio line, probably via a simple voltage divider with some DC isolation (and maybe a limiter or AGC) and use that to drive her GoPro's USB-C microphone input port. GoPro sell an adapter which receives mic or line level audio via a 3.5mm socket and feeds it to the USB-C socket on the GoPro camera. After Googling and talking to GoPro the only technical data I have been able to find on those adapters is HERE. Unfortunately GoPro's data doesn't provide the audio input voltage level at which their device will clip, distort or become damaged. QUESTIONS I AM HOPING SOMEONE CAN ANSWER: what is the maximum microphone / line audio level that can be fed into GoPro's 3.5mm microphone adapter before clipping, distortion or damage? what is the typical and maximum received audio voltage on light aircraft headsets (easy to measure but a significant trip to do so)? Any assistance, information or advice greatly appreciated. 73 Frank vk2akg.