Audio & Blueprints - Live Training Video - Audio question for the material zone setup blueprint?

Have anyone here seen the Live Training video with Zak Belica regarding audio and sound in UE4?

My question mainly focuses on the blueprint for the material zone setup. In this blueprint, Zak does not show what the “OnComponentEndOverlap(Rock Box)” node is connected to, and he does not show what happens on the right side of the blueprint. Does anyone here have any idea what he might be doing and/or connecting?

I am very new to audio in UE4 and am currently trying to create ambience for different zones on a map, and wanted to try to combine 2d and positional 3d ambience and thought this video was very well done.

You can detect overlap events with trigger volumes as a starting place!

Check out these videos, very useful: WTF Is? Volume - Trigger in Unreal Engine 4 - YouTube