Is there a link or doc somewhere “out there” that would show an example of how to use IVoiceCapture?
Doing voice capture is a pretty advanced topic (and is a relatively little-used feature in UE4) so there isn’t any high-level tutorials or documentation about it. This is pretty much the extent:
It’s turning out to be a highly requested feature: https://answers.unrealengine.com/questions/347976/basic-microphone-input-with-ue4.html