Hi,
Can you disconnect the Dynadock and run the Cleaner from here:
http://www.displaylink.com/downloads/sla.php?fileid=121
After which please try to reinstall v7.9 M0 from here:
http://www.displaylink.com/downloads/downloads.php
Lastly please reconnect your Dynadock and let me know if you still have the issue with audio.
Thanks,
James