HDMI sound via ATI graphics card

The HDMI sound device might not be detected automatically when booting the computer without the television connected. Here you can read how to make sure the drivers are always loaded.

First find your HDMI sound device, in this case card 1, device 3:

aplay -l

**** List of PLAYBACK Hardware Devices ****
...
card 1: Generic [HD-Audio Generic], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Modify the following file to force load the driver manually:

sudo gedit /etc/pulse/default.pa

Insert a line after 'module-alsa-sink':

...
#load-module module-alsa-sink
#20130701,wjv force load HDMI sound driver card 1, device 3:
load-module module-alsa-sink device=hw:1,3
...

Reboot.

Test (card 1 and device 3 --> option 1,3):

aplay -D plughw:1,3 alarm.wav
speaker-test -c 2 -r 48000 -D hw:1,3

Make sure the card is not muted:

• http://ubuntuforums.org/showthread.php?t=1668173&p=10363314#post10363314

sudo apt-get install gnome-alsamixer
alsamixer

• F6 to select the device
• M to mute/unmute