Sony rolled out firmware update for Xperia Z1, Z1 Compact, Z Ultra to fix audio bug in Android Kitkat 4.4.2. This firmware will update the build file of Sony xperia devices from 14.3.A.0.681 to 14.3.A.0.757 which will fix the sound issue for the three handsets. The user can also manually check for the update by connecting your mobile to Sony PC companion. The user can download and install the update via Sony PC companion. Sony rolled out this firmware update in specific regions for the three devices. There is no official information about global roll out of this bug fix update.