LED Cinema Display Firmware Update 1.0
This Firmware Update addresses intermittent audio issues some users have experienced while using the 27-inch LED Cinema Display.
The updater application will be installed in the /Applications/Utilities folder and will be launched automatically. Please follow the instructions in the updater application to complete the update process.
Click here for the support article covering this issue.
For additional information, please visit: OS X Mountain Lion: Firmware updates may keep reappearing in the Mac App Store.