<!--
{
  "availability" : [
    "iOS: -",
    "iPadOS: -",
    "macCatalyst: -",
    "macOS: -",
    "tvOS: -",
    "visionOS: -",
    "watchOS: -"
  ],
  "documentType" : "symbol",
  "framework" : "AVFAudio",
  "identifier" : "/documentation/AVFAudio/AVAudioNodeTapBlock",
  "metadataVersion" : "0.1.0",
  "role" : "Type Alias",
  "symbol" : {
    "kind" : "Type Alias",
    "modules" : [
      "AVFAudio"
    ],
    "preciseIdentifier" : "c:@T@AVAudioNodeTapBlock"
  },
  "title" : "AVAudioNodeTapBlock"
}
-->

# AVAudioNodeTapBlock

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

```
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

> Important:
> The framework may invoke this callback on a thread other than the main thread.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)