Channel.Angle (gb.sdl2.audio)
Property Angle As Integer
Return or set the direction of the sound in degrees.
  - 
0° is directly in front.
 
  - 
90° is directly to the right.
 
  - 
180° is directly behind.
 
  - 
270° is directly to the left.
 
  
This effect emulates a simple 3D audio effect. It's not all that realistic, but it can help improve some level of realism.
If you are looking for better positional audio, use 
gb.openal.