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

# AVAudioEnvironmentDistanceAttenuationModel.exponential

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

## Declaration

```swift
case exponential
```

## Discussion

Discussion The framework calculates this value as distanceGain = (distance / referenceDistance) ^ (-rolloffFactor).

## See Also

### Attenuation Models

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