No sound in ubuntu 11.10

Can you give the output of:

wget -O alsa-info.sh http://www.alsa-project.org/alsa-info.sh; chmod +x ./alsa-info.sh; ./alsa-info.sh

It is a terminal command, select to upload to the server and a URL will be generated. What is it?

there is a button like loudspeaker symbol top right on the panel bar..just click that your system could be muted.
then
in terminal just install vlc media player
sudo apt-get install vlc will do the installation you will be asked to enter the pw for authentication then it will install VLC Media player

  dmesg
  lspci
  lsmod
  aplay
  amixer
  alsactl
  /proc/asound/
  /sys/class/sound/
  ~/.asoundrc (etc.)

See './alsa-info.sh --help' for command line options.

Automatically upload ALSA information to www.alsa-project.org? [y/N] :

i dont understand the steps involved in the vlc media player comment...

thats just a way to install vlc media player from the terminal. to do that

press CTRL + ALT + T and terminal should open

in this terminal type this "sudo apt-get install vlc" without the quotations

it will ask for your password, type it in and press enter, it will ask you if you want to install the listed packages, press Y for yes and hit enter.

once its done you can search for VLC from the dash or in the terminal type in "vlc" without the quotations and press enter and vlc should load.

this is not entirely relevant to your problem though, this is just another media player (a very popular one yes) but most likely your issue will still be present. Have you checked your sound settings in the top menu next to the time? is it muted?

try opening your dash (press the super key) and search for settings, you should see system settings, open that up and click on sound, check to make sure nothing is muted. ect ect.

Run the command again and press Y to upload to the server and a URL will be generated.

 http://www.alsa-project.org/db/?f=c4218625b679d0d0187e83a8b8ccbb9d59af5cb3

Your mixer channels are currently muted.

Run the following command in a Terminal:

alsamixer

In this application, make sure to set all channels to high volume levels. Make sure the different speakers (especially 'Front', 'Master', and 'PCM") are NOT muted and NOT set to low volume levels in alsamixer. Move with the left and right keys on your keyboard until the "Master" item is highlighted (in red). If the letters "MM" are displayed under the volume bar, press "M" to unmute. Repeat with the "Master Mono", "Headphone", "PCM", "Front", "Surround", "Center" and "LFE" items. Press Esc when finished.

Then retest sound output using headphones and speakers.