This is a unity asset makes it possible to use multiple audio listeners in Unity.
With the default audio listener in Unity you can have only on ear in the scene. This means that the direction and volume of all sounds will be dependant on that one point.
With this asset you can have multiple audio listeners/ears in the scene. This means you can hear all the sounds close to multiple points in the scene each with their own direction.
-Multiple audio listener
-Has most features of the normal audiosource
-Ability to only play the sound for the closest camera
A demo can be found here: http://gaelvanhalst.com/ProjectDemos/MultiAudioListener/index.html
Rotate each camera to hear the direction of the sound change. Move around with both cameras to hear the effect of both cameras on different distances (volume) and direction of the fire.