---
title: AVAudioEnvironmentDistanceAttenuationModel.linear
framework: avfaudio
role: symbol
role_heading: Case
path: avfaudio/avaudioenvironmentdistanceattenuationmodel/linear
---

# AVAudioEnvironmentDistanceAttenuationModel.linear

A linear model that describes the drop-off in gain as the source moves away from the listener.

## Declaration

```swift
case linear
```

## Discussion

Discussion The framework calculates this value as distanceGain = (1 – rolloffFactor * (distance – referenceDistance) / (maximumDistance – referenceDistance)).

## See Also

### Attenuation Models

- [AVAudioEnvironmentDistanceAttenuationModel.exponential](avfaudio/avaudioenvironmentdistanceattenuationmodel/exponential.md)
- [AVAudioEnvironmentDistanceAttenuationModel.inverse](avfaudio/avaudioenvironmentdistanceattenuationmodel/inverse.md)