How do you get HDMI audio out in ubuntu 13.04?
( http://ubuntuforums.org/showthread.php?t=2147651&s=00236529ad0945d510d4c3f001c14342&p=12660421#post12660421 )

    thanks for your helo fj401971!! You were right, it was an issue of dealing s/pdif controller. to find the found the solution all i had to do was:

    1.)install pulse audio control,
    sudo apt-get install pavucontrol

    2.) install the alsa mixer daily builds.found here: https://code.launchpad.net/~ubuntu-a...aily/+packages

    3.) Once i did that, i opened pulse audio, went to configuration tab, and in the profile drop down menu there was an option for hdmi audio out. select it and kaboom, it works!

    when i checked the terminal again, the S/pdif controller was working. Previously it was disabled.

    once you do that, the hdmi controls will appear in the sound volume menu, and you can adjust the volume levels from there.


see also:
 http://forum.ubuntuusers.de/topic/zenbook-hdmi-ohne-audio/#post-6091377
 http://forum.ubuntuusers.de/topic/ton-wird-nicht-ueber-hdmi-an-tv-uebertragen/2/