This problem was solved by the OP:
The following configuration fixed the problem:
1) Added the following line to /etc/pulse/default.pa
load-module module-alsa-siice=hw:0,8
2) Added the following line to /etc/modprobe.d/alsa-base.conf
options snd-hda-intel model=mbp55 enable=1 index=0 position_fix=1
The last three parameters actually solved the problem. Before that I had to run speaker-test to get fluent sound. dmesg returned the following error but afterwards sound was okay.
hda-intel: Invalid position buffer, using LPIB read method instead.
3) I am not sure if this is related but I had temporarily success with the following grub boot parameter in /etc/default/grub
GRUB_CMDLINE_LINUX="nomodeset noacpi"
I am still not sure what the problem was. If anyone could tell me I would like to learn it. Thanks.
Some useful resources:
ftp://download.nvidia.com/XFree86/gpu-hdmi-audio-document/gpu-hdmi-audio.html
http://my.opera.com/Hoelli/blog/show.dml/1646577
Best Answer
For what it's worth, I've just resolved a no-sound problem on my HDA Intel PCH card: I ran 'alsamixer' in a terminal and unmuted the 'Line' column (with the M key).
Other info: