---
title: "AudioUnitReset(_:_:_:)"
framework: audiotoolbox
role: symbol
role_heading: Function
path: "audiotoolbox/audiounitreset(_:_:_:)"
---

# AudioUnitReset(_:_:_:)

Resets an audio unit’s render state.

## Declaration

```swift
func AudioUnitReset(_ inUnit: AudioUnit, _ inScope: AudioUnitScope, _ inElement: AudioUnitElement) -> OSStatus
```

## Parameters

- `inUnit`: The audio unit whose render state you are resetting.
- `inScope`: The audio unit scope, typically set to kAudioUnitScope_Global.
- `inElement`: The audio unit element, typically set to 0.

## Mentioned in

Migrating Your Audio Unit Host to the AUv3 API

## Return Value

Return Value A result code.

## Discussion

Discussion This function resets the render state of an audio unit. For example, with a delay or reverb type of audio unit, it clears all of the delay lines maintained within the audio unit. Typically, you call this function when an audio unit was previously rendering and was taken out of the render chain (for example, if the track it is in gets muted) and is now being added back in (for example, unmuted). Your application should reset the audio unit before adding it back to the render chain so that it does not produce audio from its delay lines that is no longer valid. This function clears memory. It does not allocate or free memory resources.

## See Also

### Initializing the Audio Unit

- [AudioUnitInitialize(_:)](audiotoolbox/audiounitinitialize(_:).md)
- [AudioUnitUninitialize(_:)](audiotoolbox/audiounituninitialize(_:).md)
- [AudioUnitProcess(_:_:_:_:_:)](audiotoolbox/audiounitprocess(_:_:_:_:_:).md)
- [AudioUnitProcessMultiple(_:_:_:_:_:_:_:_:)](audiotoolbox/audiounitprocessmultiple(_:_:_:_:_:_:_:_:).md)
- [AudioUnit](audiotoolbox/audiounit.md)