An author asked me how to make a sound cone in FMOD for X-Plane.
For example, our Cessna features recordings of the engines from four different mic positions (front, left, right, and back) - our engine sound event contains four sub-sound events, with sound cones modulating when the sound can be heard. Think of a 90 degree cone sticking out from the engine to the front, the right, etc. Only if the listener is in the sound cone can you hear it.
Here's the trick: X-Plane provides two special parameters that give you the bearing of the listener relative to the event. From this you can create your attenuation shapes.