Audio Volume / Ambient Zone Settings Have No Affect on Audio

Very sorry if I’m missing the obvious but I’m new to Unreal (v4.8.2) and, although setting up an Occlusion Zone looks really simple, when testing and walking in / out of the zone, it has no affect on the audio as I’d expect.

I’m using basic Sound Actors, being thrown in various places around the level so I’m expecting sounds outside of the box to attenuate (like going into a building) and vice versa…

See attached screen grab detailing my settings. Please Note: This is not a game so doesn’t have a player… when in Game Simulation I’m essentially moving a camera around… maybe this has something to do with it?

Any help and guidance is HUGELY appreciated.