How the Spatial Placement of Sound Aids Acting Performance

I’ve been heavily involved in NC State University Theatre’s performance of Mr. Burns: A Post Electric Play as an actor that is on stage for a good majority of the show. This experience has really made me consider the importance of the spatial placement of sound effects, specifically because of two separate instances in the show.
The first instance of a well placed sound effect really helping my immersion as an actor (as well as with the audience’s experience) is the sound of a campfire crackling on stage. We have a fire pit on the set that uses a humidifier, fan, and lights to make a flame that looks realistic from the audience. The fire is not visually convincing from my location right next to it, but thanks to a speaker placed right next to the humidifier, the sound of a crackling fire comes directly from where it feels like it should. This is a subtle thing, but it is so much more convincing than if the fire sound was coming from an overhead speaker somewhere in the house, and really helps us actors act as if we are sitting around a fire. No doubt the audience notices that this seems really authentic as well. In the more quiet moments of the show, the fire is all that can be heard, and it feels so natural.
The second very convincing placement of a sound effect is something of a spoiler if you haven’t watched the show yet. That being the placement of some gun cocking and gunshot sound effects right before the intermission. These sounds are meant to come from somewhere off to the stage right of where the audience is, and that is where the speakers are placed to make the sound. It’s very easy to act like someone is shooting you from a certain direction when you can clearly hear the gunshots coming loudly from that direction. Judging by the faces of the startled people in the audience, they agree that it feels convincing.
This same concept of spatial positioning of sound is how first person video games and surround sound movies truly immerse the audience in a way that mono-directional sound cannot. When you play Halo for example, if you are wearing headphones you can tell which direction the sounds of battle or footsteps are coming from, and it really heightens the experience. Any chance a director of any type of project has to include multi-directional sound, they should take it.