---
title: microphoneInjectionCapabilitiesChangeNotification
framework: avfaudio
role: symbol
role_heading: Type Property
path: avfaudio/avaudiosession/microphoneinjectioncapabilitieschangenotification
---

# microphoneInjectionCapabilitiesChangeNotification

A notification the system posts when its capability to inject audio into an input stream changes.

## Declaration

```swift
class let microphoneInjectionCapabilitiesChangeNotification: NSNotification.Name
```

## Discussion

Discussion Query the notification’s userInfo dictionary for AVAudioSessionMicrophoneInjectionIsAvailableKey to determine whether microphone injection is available.

## Topics

### User-information keys

- [AVAudioSessionMicrophoneInjectionIsAvailableKey](avfaudio/avaudiosessionmicrophoneinjectionisavailablekey.md)

## See Also

### Enabling adding audio to calls

- [isMicrophoneInjectionAvailable](avfaudio/avaudiosession/ismicrophoneinjectionavailable.md)
- [preferredMicrophoneInjectionMode](avfaudio/avaudiosession/preferredmicrophoneinjectionmode.md)
- [setPreferredMicrophoneInjectionMode(_:)](avfaudio/avaudiosession/setpreferredmicrophoneinjectionmode(_:).md)
- [AVAudioSession.MicrophoneInjectionMode](avfaudio/avaudiosession/microphoneinjectionmode.md)