Spatial Sound from 360° VR Video Player

I successfully built a 3D 360° video player using the Unity Skybox Panoramic Shader.

The problem now is that its 5.1 surround soundtrack isn't recognized by Unity or Oculus.

I already tried Edit > Project Settings > Audio > Spatializer Plugin > OculusSpatializer with no difference.

> How can Unity/Oculus recognize the 5.1 sound and make it react to my head movements?