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# occlusion

A value that simulates filtering of the direct and reverb paths of sound due to an obstacle.

```
var occlusion: Float { get set }
```

## Discussion

The value of `obstruction` is in decibels. The system blocks the direct and reverb paths of sound between the source and listener.

The default value is `0.0`, and the range of valid values is `-100` to `0`. Only the [`AVAudioEnvironmentNode`](/documentation/AVFAudio/AVAudioEnvironmentNode) class implements this property.

---

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