---
title: kAudioSessionProperty_AudioInputAvailable
framework: audiotoolbox
role: symbol
role_heading: Global Variable
path: audiotoolbox/kaudiosessionproperty_audioinputavailable
---

# kAudioSessionProperty_AudioInputAvailable

Indicates if audio input is available (a nonzero value) or not (a value of 0).

## Declaration

```swift
var kAudioSessionProperty_AudioInputAvailable: Int { get }
```

## Discussion

Discussion A read-only UInt32 value, interpreted as a Boolean value. Use this property, rather than the device model, to determine if audio input is available. You can listen for changes in the value of this property using a callback function.  For instance, if a user plugs a headset into an iPod touch (2nd generation), audio input becomes available via the wired microphone and your callback is invoked. See AudioSessionAddPropertyListener(_:_:_:).

## See Also

### 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_ServerDied](audiotoolbox/kaudiosessionproperty_serverdied.md)
- [kAudioSessionProperty_OtherMixableAudioShouldDuck](audiotoolbox/kaudiosessionproperty_othermixableaudioshouldduck.md)