Maybe it would be possible to add discrete sounds to enhance sensations in the game.
Of course, they could be disabled or controlled.
For instance a smooth breeze above the base pushing the light clouds that we can see.
In the buildings sounds related to the functions:
sparks or zap for tesla.
vapor or pneumatic sounds in the gas rig (air blow into a pipe).
orders (not distinctive distorted by loudspeaker to avoid languages and translation) and noises in the squad dock (like in an aircraft carrier: lifts, metallic noises, vehicles)
foundry and mechanical assembly noises in the robot factory.
servo and keyboard noises in the robot research lab.
electronic and ballistic noises in the components lab.
loading ammo, heavy rotating and alert noises in the turrets.
radio transmissions and printer noises in the QG.
bips and scanning sounds in the control center.