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# PHASEDistanceModelParameters

A base class for a sound’s rate of change over distance.

```
class PHASEDistanceModelParameters
```

## Overview

When your app outputs sound with a 3D position and orientation, designate a subclass of this class to indicate the manner in which PHASE changes sound with distance. Assign an instance of either [`PHASEGeometricSpreadingDistanceModelParameters`](/documentation/PHASE/PHASEGeometricSpreadingDistanceModelParameters) or [`PHASEEnvelopeDistanceModelParameters`](/documentation/PHASE/PHASEEnvelopeDistanceModelParameters), depending on your app’s needs, to the [`PHASESpatialMixerDefinition`](/documentation/PHASE/PHASESpatialMixerDefinition) class’s [`distanceModelParameters`](/documentation/PHASE/PHASESpatialMixerDefinition/distanceModelParameters) property.

## Topics

### Fading the Sound

[`fadeOutParameters`](/documentation/PHASE/PHASEDistanceModelParameters/fadeOutParameters)

A distance over which the framework fades out the mixer’s sound.


---

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