---
title: Audio Session Property Identifiers
framework: audiotoolbox
role: collectionGroup
role_heading: API Collection
path: audiotoolbox/1618455-audio-session-property-identifie
---

# Audio Session Property Identifiers

Property identifiers used with Audio Session Services in iOS.

## Overview

Overview Use these property identifiers in concert with the AudioSessionGetProperty(_:_:_:), AudioSessionSetProperty(_:_:_:), and AudioSessionAddPropertyListener(_:_:_:) functions.

## Topics

### Constants

- [kAudioSessionProperty_PreferredHardwareSampleRate](audiotoolbox/kaudiosessionproperty_preferredhardwaresamplerate.md)
- [kAudioSessionProperty_PreferredHardwareIOBufferDuration](audiotoolbox/kaudiosessionproperty_preferredhardwareiobufferduration.md)
- [kAudioSessionProperty_AudioCategory](audiotoolbox/kaudiosessionproperty_audiocategory.md)
- [kAudioSessionProperty_AudioRouteChange](audiotoolbox/kaudiosessionproperty_audioroutechange.md)
- [kAudioSessionProperty_CurrentHardwareSampleRate](audiotoolbox/kaudiosessionproperty_currenthardwaresamplerate.md)
- [kAudioSessionProperty_CurrentHardwareInputNumberChannels](audiotoolbox/kaudiosessionproperty_currenthardwareinputnumberchannels.md)
- [kAudioSessionProperty_CurrentHardwareOutputNumberChannels](audiotoolbox/kaudiosessionproperty_currenthardwareoutputnumberchannels.md)
- [kAudioSessionProperty_CurrentHardwareOutputVolume](audiotoolbox/kaudiosessionproperty_currenthardwareoutputvolume.md)
- [kAudioSessionProperty_CurrentHardwareInputLatency](audiotoolbox/kaudiosessionproperty_currenthardwareinputlatency.md)
- [kAudioSessionProperty_CurrentHardwareOutputLatency](audiotoolbox/kaudiosessionproperty_currenthardwareoutputlatency.md)
- [kAudioSessionProperty_CurrentHardwareIOBufferDuration](audiotoolbox/kaudiosessionproperty_currenthardwareiobufferduration.md)
- [kAudioSessionProperty_OtherAudioIsPlaying](audiotoolbox/kaudiosessionproperty_otheraudioisplaying.md)
- [kAudioSessionProperty_OverrideAudioRoute](audiotoolbox/kaudiosessionproperty_overrideaudioroute.md)
- [kAudioSessionProperty_AudioInputAvailable](audiotoolbox/kaudiosessionproperty_audioinputavailable.md)
- [kAudioSessionProperty_ServerDied](audiotoolbox/kaudiosessionproperty_serverdied.md)
- [kAudioSessionProperty_OtherMixableAudioShouldDuck](audiotoolbox/kaudiosessionproperty_othermixableaudioshouldduck.md)
- [kAudioSessionProperty_OverrideCategoryMixWithOthers](audiotoolbox/kaudiosessionproperty_overridecategorymixwithothers.md)
- [kAudioSessionProperty_OverrideCategoryDefaultToSpeaker](audiotoolbox/kaudiosessionproperty_overridecategorydefaulttospeaker.md)
- [kAudioSessionProperty_OverrideCategoryEnableBluetoothInput](audiotoolbox/kaudiosessionproperty_overridecategoryenablebluetoothinput.md)
- [kAudioSessionProperty_InterruptionType](audiotoolbox/kaudiosessionproperty_interruptiontype.md)
- [kAudioSessionProperty_Mode](audiotoolbox/kaudiosessionproperty_mode.md)
- [kAudioSessionProperty_InputSources](audiotoolbox/kaudiosessionproperty_inputsources.md)
- [kAudioSessionProperty_OutputDestinations](audiotoolbox/kaudiosessionproperty_outputdestinations.md)
- [kAudioSessionProperty_InputSource](audiotoolbox/kaudiosessionproperty_inputsource.md)
- [kAudioSessionProperty_OutputDestination](audiotoolbox/kaudiosessionproperty_outputdestination.md)
- [kAudioSessionProperty_InputGainAvailable](audiotoolbox/kaudiosessionproperty_inputgainavailable.md)
- [kAudioSessionProperty_InputGainScalar](audiotoolbox/kaudiosessionproperty_inputgainscalar.md)
- [kAudioSessionProperty_AudioRouteDescription](audiotoolbox/kaudiosessionproperty_audioroutedescription.md)

## See Also

### Audio Session Support

- [Audio Session Categories](audiotoolbox/1618427-audio-session-categories.md)
- [Audio Session Modes](audiotoolbox/1618405-audio-session-modes.md)
- [Audio Session Category Route Overrides](audiotoolbox/1618372-audio-session-category-route-ove.md)
- [Audio Session Activation Flags](audiotoolbox/1618357-audio-session-activation-flags.md)
- [Audio Session Interruption States](audiotoolbox/1618425-audio-session-interruption-state.md)
- [AudioSessionInterruptionType](audiotoolbox/audiosessioninterruptiontype.md)