Listener Properties

The direction (also called "at vector") is the vector pointing forward from the listener's perspective. Together with the up vector, it defines the 3D orientation of the listener in the scene. The direction vector doesn't have to be normalized. The default listener's direction is (0, 0, -1).

The volume is a number between 0 and 100; it is combined with the individual volume of each sound / music. The default value for the volume is 100 (maximum).

3D position of the listener (default is (0, 0, 0))

The up vector is the vector that points upward from the listener's perspective. Together with the direction, it defines the 3D orientation of the listener in the scene. The up vector doesn't have to be normalized. The default listener's up vector is (0, 1, 0). It is usually not necessary to change it, especially in 2D scenarios.