The video says the same thing as the log transcript (pretty much) but it tacks on "elsewhere" at the very end.
the "mind" the log speaks of - - safe to assume that it's Gravemind?
If the the parasite have done this "elsewhere", maybe the Gravemind we all know and love isn't the only Gravemind. Or the Forerunners did these experiments once before and they got out of hand
I'm playing around with the 719Hz thing in a audio program I have. I (currently) can't find anything special
I think I hear a voice in the 719Hz file