She sent audio to Fiona that hadn't been manipulated yet because that would've obviously made Fiona suspicious. Then Fiona leaked that.
Well, it was manipulated in that it was edited.
A reminder for everyone (correct me if I'm wrong)
#1. The first leak was by Fiona, given to her by Bella and released without permission (posted on Reddit), and contains only Chris himself speaking. Edited in a way that is extremely suspicious, since it cuts so erratically that Chris often interrupts himself. I believe this was about 5 minutes?
#2-#3. The second and third leaks were released by Bella/Louis, and the third leak is a VIDEO file from which the audio was likely sourced (recorded with an iPad, the video is the rear-facing camera being placed face-down on a bed or something). These leaks contained Bella's voice, but were obviously edited in a way that excluded parts of the conversation. The second was about 9 minutes, the third was around 15 minutes.
#4. The fourth leak was given to
@GiBi by Bella/Louis. It has a few small differences between itself and the second leak (no video on this one), but the most obvious and unnecessary is the inclusion of the disclosure of personal and traumatic events from Fiona's past (as gleefully told to Chris by Bella). There is obviously still more to the call, anywhere from 34 minutes to 3 or more hours. Draw your own conclusions on Isabella Janke's motivation to release this version, and GiBi's seemingly unquestioning release of it. This leak was about 21 minutes long.
As far as Voice Changer metadata, only #2 and #3 had it, as far as I remember.
EDIT: Forgot there were 2 calls released by Bella and Louis, the latter of which was a video.