I recently ran into this myself, when I was recording my audiobook last weekend. It seems that I use kind of a lot of words that I am not 100% sure how to pronounce. (John Herried called this “Homeschooler’s Syndrome.” Oh lawsy, there she goes again, attacking homeschoolers!!!1!) It happened a few times, but the one I really struggled with was “minutiae.” I asked the producer, and he didn’t know, either. I think I ended up saying “my-NOO-shee-aye.” I did my best to make it sound authoritative.
I just love it when little fissures of naivete are introduced into the professional world like this. We’re all faking it, at one level or another.