---
title: obstruction
framework: avfaudio
role: symbol
role_heading: Instance Property
path: avfaudio/avaudio3dmixing/obstruction
---

# obstruction

A value that simulates filtering of the direct path of sound due to an obstacle.

## Declaration

```swift
var obstruction: Float { get set }
```

## Discussion

Discussion The value of obstruction is in decibels. The system blocks only the direct path 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 class implements this property.

## See Also

### Getting the 3D Mixing Parameters

- [occlusion](avfaudio/avaudio3dmixing/occlusion.md)
- [position](avfaudio/avaudio3dmixing/position.md)
- [rate](avfaudio/avaudio3dmixing/rate.md)
- [pointSourceInHeadMode](avfaudio/avaudio3dmixing/pointsourceinheadmode.md)
- [reverbBlend](avfaudio/avaudio3dmixing/reverbblend.md)
- [sourceMode](avfaudio/avaudio3dmixing/sourcemode.md)