Download the update and while you're doing so...
Updates to our documentation, too. :)
Oh yeah and while you're playing with that terrain editor, try changing brush parameters and listen closely. Almost every visual thing is linked to how it sounds, for a cohesive and visceral experience moving the virtual earth. Pretty fun huh?
Please share your audio feedback on the new release (September 8, 2017 - 18.104.22.168873) here.
P.S. I'm aware there's a bug with some UI sounds playing twice at the same time. A fix is coming soon.