<!--
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    "DriverKit: 21.0 -"
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  "framework" : "AudioDriverKit",
  "identifier" : "/documentation/AudioDriverKit/IOUserAudioLevelControl/HandleChangeDecibelValue",
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  "title" : "HandleChangeDecibelValue"
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# HandleChangeDecibelValue

Tells the slider control the decibel value is changing.

```
virtual kern_return_t HandleChangeDecibelValue(float in_decibel_value);
```

## Parameters

`in_decibel_value`

The new decibel value to set.

## Return Value

<doc://com.apple.documentation/documentation/DriverKit/kIOReturnSuccess> on success, or another value if an error occurs. For a list of error codes, see <doc://com.apple.documentation/documentation/DriverKit/error-codes>.

## Discussion

The default implementation calls [`SetDecibelValue`](/documentation/AudioDriverKit/IOUserAudioLevelControl/SetDecibelValue) and returns <doc://com.apple.documentation/documentation/DriverKit/kIOReturnSuccess>. Subclass and override this method to handle changes to the stream format and return <doc://com.apple.documentation/documentation/DriverKit/kIOReturnSuccess> upon success.

---

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