---
title: kAUVoiceIOProperty_MutedSpeechActivityEventListener
framework: audiotoolbox
role: symbol
role_heading: Global Variable
path: audiotoolbox/kauvoiceioproperty_mutedspeechactivityeventlistener
---

# kAUVoiceIOProperty_MutedSpeechActivityEventListener

A property to register a listener that the system calls when it detects speech while the user has the microphone muted.

## Declaration

```swift
var kAUVoiceIOProperty_MutedSpeechActivityEventListener: AudioUnitPropertyID { get }
```

## Discussion

Discussion To use this API, your app must implement mute using the kAUVoiceIOProperty_MuteOutput property.

## See Also

### Observing muted speech

- [AUVoiceIOMutedSpeechActivityEventListener](audiotoolbox/auvoiceiomutedspeechactivityeventlistener.md)
- [AUVoiceIOSpeechActivityEvent](audiotoolbox/auvoiceiospeechactivityevent.md)