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# AUParameterTree

An object that represents a top-level group node that contains all of an audio unit’s parameters.

```
class AUParameterTree
```

## Overview

An audio unit’s parameters are organized into a tree containing groups and parameters (groups may be nested).

The parameter tree is KVO-compliant. An audio unit may choose to dynamically rearrange the tree; when doing so, it must issue a KVO notification on the audio unit’s [`parameterTree`](/documentation/AudioToolbox/AUAudioUnit/parameterTree) property.

## Topics

### Obtaining Tree Parameters

[`-  parameterWithAddress:`](/documentation/AudioToolbox/AUParameterTree/parameter(withAddress:))

Searches the tree for a parameter with a specific address.

[`-  parameterWithID:scope:element:`](/documentation/AudioToolbox/AUParameterTree/parameter(withID:scope:element:))

Searches the tree for a specific version 2 audio unit parameter.

### Audio Unit Implementations

These methods are only of interest to audio unit subclasses.

[`+  createParameterWithIdentifier:name:address:min:max:unit:unitName:flags:valueStrings:dependentParameters:`](/documentation/AudioToolbox/AUParameterTree/createParameter(withIdentifier:name:address:min:max:unit:unitName:flags:valueStrings:dependentParameters:))

Creates a single parameter object.

[`+  createGroupWithIdentifier:name:children:`](/documentation/AudioToolbox/AUParameterTree/createGroup(withIdentifier:name:children:))

Creates a parameter group object.

[`+  createGroupTemplate:`](/documentation/AudioToolbox/AUParameterTree/createGroupTemplate(_:))

Creates a template group which may be used as a prototype for further group instances.

[`+  createGroupFromTemplate:identifier:name:addressOffset:`](/documentation/AudioToolbox/AUParameterTree/createGroup(fromTemplate:identifier:name:addressOffset:))

Initializes a group as a copied instance of a template group.

[`+  createTreeWithChildren:`](/documentation/AudioToolbox/AUParameterTree/createTree(withChildren:))

Creates a parameter tree object.

## Relationships

### Conforms To

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

[`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol)

[`CVarArg`](/documentation/Swift/CVarArg)

[`Equatable`](/documentation/Swift/Equatable)

[`NSCoding`](/documentation/Foundation/NSCoding)

[`Hashable`](/documentation/Swift/Hashable)

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

[`NSSecureCoding`](/documentation/Foundation/NSSecureCoding)

### Inherits From

[`AUParameterGroup`](/documentation/AudioToolbox/AUParameterGroup)

---

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