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# kAudioSession_AudioRouteChangeKey_Reason

Identifies the reason for the audio route change.

```
var kAudioSession_AudioRouteChangeKey_Reason: String { get }
```

## Discussion

Value is a <doc://com.apple.documentation/documentation/CoreFoundation/CFNumber> object that identifies the reason for the audio route change. See [Audio Route Change Reasons](/documentation/AudioToolbox/1618380-audio-route-change-reasons).

## Discussion

> Note:
> It is typically more convenient to instead use the <doc://com.apple.documentation/documentation/CoreFoundation/CFString> version of this constant, ``doc://com.apple.audiotoolbox/documentation/AudioToolbox/kAudioSession_RouteChangeKey_Reason``.

---

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