Start the music app, play a tune then press the home button twice. Swipe to the right, and you'll have the option to use Airplay. You'll probably find that iPhone is not in the list; so play the music to the AirPlay output option.
Go back to the home screen, then press the home button twice. Kill the music app, and you should get sound back; although there are reports that the iPhone may believe it's still in a dock connector.
Come up with any other workarounds? Describe your experiences in the comments field below.
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