---
title: AUParameterListenerProc
framework: audiotoolbox
role: symbol
role_heading: Type Alias
path: audiotoolbox/auparameterlistenerproc
---

# AUParameterListenerProc

## Declaration

```swift
typealias AUParameterListenerProc = (UnsafeMutableRawPointer?, UnsafeMutableRawPointer?, UnsafePointer<AudioUnitParameter>, AudioUnitParameterValue) -> Void
```

## See Also

### Monitoring Parameter Changes

- [AUListenerCreateWithDispatchQueue(_:_:_:_:)](audiotoolbox/aulistenercreatewithdispatchqueue(_:_:_:_:).md)
- [AUListenerCreate(_:_:_:_:_:_:)](audiotoolbox/aulistenercreate(_:_:_:_:_:_:).md)
- [AUParameterListenerNotify(_:_:_:)](audiotoolbox/auparameterlistenernotify(_:_:_:).md)
- [AUParameterFormatValue(_:_:_:_:)](audiotoolbox/auparameterformatvalue(_:_:_:_:).md)
- [AUParameterSet(_:_:_:_:_:)](audiotoolbox/auparameterset(_:_:_:_:_:).md)
- [AUParameterValueFromLinear(_:_:)](audiotoolbox/auparametervaluefromlinear(_:_:).md)
- [AUParameterValueToLinear(_:_:)](audiotoolbox/auparametervaluetolinear(_:_:).md)
- [AUParameterListenerBlock](audiotoolbox/auparameterlistenerblock.md)
- [AUParameterListenerRef](audiotoolbox/auparameterlistenerref.md)
- [AUImplementorDisplayNameWithLengthCallback](audiotoolbox/auimplementordisplaynamewithlengthcallback.md)
- [AUImplementorStringFromValueCallback](audiotoolbox/auimplementorstringfromvaluecallback.md)
- [AUImplementorValueFromStringCallback](audiotoolbox/auimplementorvaluefromstringcallback.md)