---
title: "AudioUnitInitialize(_:)"
framework: audiotoolbox
role: symbol
role_heading: Function
path: "audiotoolbox/audiounitinitialize(_:)"
---

# AudioUnitInitialize(_:)

Initializes an audio unit

## Declaration

```swift
func AudioUnitInitialize(_ inUnit: AudioUnit) -> OSStatus
```

## Parameters

- `inUnit`: The audio unit to initialize.

## Mentioned in

Migrating Your Audio Unit Host to the AUv3 API

## Return Value

Return Value A result code.

## Discussion

Discussion On successful initialization, the audio formats for input and output are valid and the audio unit is ready to render. During initialization, an audio unit allocates memory according to the maximum number of audio frames it can produce in response to a single render call. Usually, the state of an audio unit (such as its I/O formats and memory allocations) cannot be changed while an audio unit is initialized.

## See Also

### Initializing the Audio Unit

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