---
title: I/O Audio Unit Properties
framework: audiotoolbox
role: collectionGroup
role_heading: API Collection
path: audiotoolbox/1534116-i_o_audio_unit_properties
---

# I/O Audio Unit Properties

Properties for Apple I/O audio units (sometimes called output units).

## Topics

### Properties

- [kAudioOutputUnitProperty_ChannelMap](audiotoolbox/kaudiooutputunitproperty_channelmap.md)
- [kAudioOutputUnitProperty_CurrentDevice](audiotoolbox/kaudiooutputunitproperty_currentdevice.md)
- [kAudioOutputUnitProperty_EnableIO](audiotoolbox/kaudiooutputunitproperty_enableio.md)
- [kAudioOutputUnitProperty_HasIO](audiotoolbox/kaudiooutputunitproperty_hasio.md)
- [kAudioOutputUnitProperty_SetInputCallback](audiotoolbox/kaudiooutputunitproperty_setinputcallback.md)
- [kAudioOutputUnitProperty_StartTime](audiotoolbox/kaudiooutputunitproperty_starttime.md)
- [kAudioOutputUnitProperty_StartTimestampsAtZero](audiotoolbox/kaudiooutputunitproperty_starttimestampsatzero.md)
- [kAudioOutputUnitProperty_IsRunning](audiotoolbox/kaudiooutputunitproperty_isrunning.md)

## See Also

### Input/Output

- [Inter-App Output Unit Property IDs](audiotoolbox/1621039-inter-app-output-unit-property-ids.md)
- [Inter-App Audio Unit Property IDs](audiotoolbox/1621038-inter-app-audio-unit-property-ids.md)
- [Output Unit Parameters](audiotoolbox/1389916-output_unit_parameters.md)
- [AUNetReceive Properties](audiotoolbox/1534109-aunetreceive-properties.md)
- [AUNetSend Properties](audiotoolbox/1534207-aunetsend-properties.md)
- [AUNetSend Parameters](audiotoolbox/1389633-aunetsend-parameters.md)
- [AUNetReceive Parameters](audiotoolbox/1389920-aunetreceive-parameters.md)
- [AUNetSendPresetFormat Properties](audiotoolbox/1534212-aunetsendpresetformat-properties.md)
- [Net Status Audio Unit Parameters](audiotoolbox/1389891-net-status-audio-unit-parameters.md)
- [I/O Audio Unit Function Selectors](audiotoolbox/1585807-i_o_audio_unit_function_selector.md)
- [AudioOutputUnitMIDICallbacks](audiotoolbox/audiooutputunitmidicallbacks.md)
- [AudioOutputUnitStartAtTimeParams](audiotoolbox/audiooutputunitstartattimeparams.md)