---
title: AudioUnitPropertyID
framework: audiotoolbox
role: symbol
role_heading: Type Alias
path: audiotoolbox/audiounitpropertyid
---

# AudioUnitPropertyID

The data type for audio unit property keys.

## Declaration

```swift
typealias AudioUnitPropertyID = UInt32
```

## Discussion

Discussion An audio unit property is a key-value pair for a configuration setting, such as audio data stream format. The properties for Apple-supplied audio units are described in Audio Unit Properties.

## See Also

### Audio Unit Types

- [ScheduledAudioFileRegion](audiotoolbox/scheduledaudiofileregion.md)
- [ScheduledAudioSlice](audiotoolbox/scheduledaudioslice.md)
- [ScheduledAudioFileRegionCompletionProc](audiotoolbox/scheduledaudiofileregioncompletionproc.md)
- [ScheduledAudioSliceCompletionProc](audiotoolbox/scheduledaudioslicecompletionproc.md)
- [MIDIChannelNumber](audiotoolbox/midichannelnumber.md)
- [AUAudioObjectID](audiotoolbox/auaudioobjectid.md)
- [AUMIDICIProfileChangedBlock](audiotoolbox/aumidiciprofilechangedblock.md)
- [AUAudioChannelCount](audiotoolbox/auaudiochannelcount.md)
- [AUAudioFrameCount](audiotoolbox/auaudioframecount.md)
- [AUAudioUnitStatus](audiotoolbox/auaudiounitstatus.md)
- [AUEventListenerProc](audiotoolbox/aueventlistenerproc.md)
- [AUEventListenerRef](audiotoolbox/aueventlistenerref.md)
- [AUEventSampleTime](audiotoolbox/aueventsampletime.md)
- [AUImplementorValueObserver](audiotoolbox/auimplementorvalueobserver.md)
- [AUImplementorValueProvider](audiotoolbox/auimplementorvalueprovider.md)