Did you make sure that you installed AMD audio driver when you did the installation of your crimson driver ( older crimson since this is based on the terascale architecture.)
Plus could you please give more info about the rest of your system.
As a bonus tip/workaround you can plug an audio cable into your desktop and tv and have sound that way and use your intergrated realtek audio device.
Just to make sure you can try to enable AMD digital display audio in your sound department of the control panel
Hope this helps.