---
title: AudioUnitParameter
framework: audiotoolbox
role: symbol
role_heading: Structure
path: audiotoolbox/audiounitparameter
---

# AudioUnitParameter

An adjustable audio unit attribute such as volume, pitch, or filter cutoff frequency.

## Declaration

```swift
struct AudioUnitParameter
```

## Overview

Overview This data structure is used by functions declared in the AudioToolbox/AudioUnitUtilities.h header file in macOS. An audio unit parameter is uniquely identified by the combination of its scope, element, and ID.

## Topics

### Initializers

- [init(mAudioUnit:mParameterID:mScope:mElement:)](audiotoolbox/audiounitparameter/init(maudiounit:mparameterid:mscope:melement:)-2hcn6.md)
- [init(mAudioUnit:mParameterID:mScope:mElement:)](audiotoolbox/audiounitparameter/init(maudiounit:mparameterid:mscope:melement:)-55k5j.md)

### Instance Properties

- [mAudioUnit](audiotoolbox/audiounitparameter/maudiounit.md)
- [mElement](audiotoolbox/audiounitparameter/melement.md)
- [mParameterID](audiotoolbox/audiounitparameter/mparameterid.md)
- [mScope](audiotoolbox/audiounitparameter/mscope.md)

## Relationships

### Conforms To

- [BitwiseCopyable](swift/bitwisecopyable.md)

## See Also

### Structures

- [AudioUnitConnection](audiotoolbox/audiounitconnection.md)
- [AudioUnitEvent](audiotoolbox/audiounitevent.md)
- [AudioUnitExternalBuffer](audiotoolbox/audiounitexternalbuffer.md)
- [AudioUnitFrequencyResponseBin](audiotoolbox/audiounitfrequencyresponsebin.md)
- [AudioUnitMeterClipping](audiotoolbox/audiounitmeterclipping.md)
- [AudioUnitMIDIControlMapping](audiotoolbox/audiounitmidicontrolmapping.md)
- [AudioUnitOtherPluginDesc](audiotoolbox/audiounitotherplugindesc.md)
- [AudioUnitParameterEvent](audiotoolbox/audiounitparameterevent.md)
- [AudioUnitParameterHistoryInfo](audiotoolbox/audiounitparameterhistoryinfo.md)
- [AudioUnitParameterNameInfo](audiotoolbox/audiounitparameternameinfo.md)
- [AudioUnitParameterIDName](audiotoolbox/audiounitparameteridname.md)
- [AudioUnitParameterInfo](audiotoolbox/audiounitparameterinfo.md)
- [AudioUnitParameterOptions](audiotoolbox/audiounitparameteroptions.md)
- [AudioUnitParameterStringFromValue](audiotoolbox/audiounitparameterstringfromvalue.md)
- [AudioUnitParameterValueFromString](audiotoolbox/audiounitparametervaluefromstring.md)