---
title: kSpeechErrorCFCallBack
framework: applicationservices
role: symbol
role_heading: Global Variable
path: applicationservices/kspeecherrorcfcallback
---

# kSpeechErrorCFCallBack

Set the callback function to be called when an error is encountered during the processing of an embedded command.

## Declaration

```swift
let kSpeechErrorCFCallBack: CFString
```

## Discussion

Discussion When a Speech Synthesis Manager function returns an error directly, the error callback function is not called. The callback function is passed information about the most recent error; it can determine information about the oldest pending error by using the speech information property kSpeechErrorsProperty. The value associated with this property is CFNumber object whose value is a pointer to an application-defined error callback function, whose syntax is described in SpeechErrorCFProcPtr. Passing a CFNumber object that contains the value NULL for the value of this property disables the error callback function. This property works with the SetSpeechProperty(_:_:_:) function.