Obviously, the actual recording medium is moot since it works on both digital "virtual" recorders as well as magnetic tape and all. The microphone should, I would think, be moot, since an eardrum should be able to vibrate just as well as a microphone's membrane. That really just leaves the wiring between the microphone and the data-recording part, which I don't think would/could/should pick up on such things, unless one can mundanely (with equipment and all) emit electromagnetic fields that would properly "translate" as sound the microphone could've picked up.
Any guesses? Other than "accept the miracle and move on", of course.
Crossposted to paranormal_news