unity spatializer user params (script)

I'm trying to find documentation on what the parameters are controled in this script. It comes with the Native Audio SDK demo where you choose the spatialization via "demo spatializer". In the demo, there is a scene called Spatilization and this script is on all the audio sources, but i can't find any documentation explaining what the script does.

See attached file of the script attached to the audio source in the demo

Here's the script

// The spatialization API is only supported by the final Unity 5.2 version and newer.
// If you get script compile errors in this file, comment out the line below.
#define ENABLE_SPATIALIZER_API
using UnityEngine;
using System.Collections;
public class SpatializerUserParams : MonoBehaviour
{
#if ENABLE_SPATIALIZER_API
public bool EnableSpatialization = true;
public float DistanceAttn = 1.0f;
public float FixedVolume = 0.0f;
public float CustomRolloff = 0.0f;
#endif
void Start()
{
}
void Update()
{
var source = GetComponent<AudioSource>();
#if ENABLE_SPATIALIZER_API
source.SetSpatializerFloat(0, DistanceAttn);
source.SetSpatializerFloat(1, FixedVolume);
source.SetSpatializerFloat(2, CustomRolloff);
source.GetSpatializerFloat(0, out DistanceAttn); // Get back clipped parameters from plugin
source.GetSpatializerFloat(1, out FixedVolume);
source.GetSpatializerFloat(2, out CustomRolloff);
source.spatialize = EnableSpatialization;
#endif
}
}