---
title: AVAudioNodeTapBlock
framework: avfaudio
role: symbol
role_heading: Type Alias
path: avfaudio/avaudionodetapblock
---

# AVAudioNodeTapBlock

The block that receives copies of the output of an audio node.

## Declaration

```swift
typealias AVAudioNodeTapBlock = (AVAudioPCMBuffer, AVAudioTime) -> Void
```

## Parameters

- `buffer`: A buffer of audio the system captures from the output of an audio node.
- `when`: The time the system captures the buffer.

## Discussion

Discussion important: The framework may invoke this callback on a thread other than the main thread.

## See Also

### Installing and Removing an Audio Tap

- [installAudioTap(onBus:bufferSize:format:tapProvider:)](avfaudio/avaudionode/installaudiotap(onbus:buffersize:format:tapprovider:).md)
- [installTap(onBus:bufferSize:format:block:)](avfaudio/avaudionode/installtap(onbus:buffersize:format:block:).md)
- [removeTap(onBus:)](avfaudio/avaudionode/removetap(onbus:).md)