Comment 89 for bug 438318

Hi, this is Pietro checking back in to confirm that Kristofer's fix worked for me in 9.10, and works (and is still necessary) in 10.04. At least for my Toshiba Netbook NB205. So if you have installed or just updated to 10.04 Lucid, here are instructions to get sound working the noob way:
Go to: Applications > Accessories > Terminal.
This will open what is called a "shell" window, and in the new window it will display [your-username]@[your-computer-name] followed by a prompt.
Here you can type in the following text:

sudo gedit /etc/modprobe.d/alsa-base.conf

Hit <ENTER>, and this command starts the text editor "Gedit," and directs it to open the file "alsa-base.conf" within the directories "/etc/modprobe.d". Once Gedit opens the file, scroll down to the bottom of the file and paste (or type) in the following text:

options snd-hda-intel index=0 model=auto

Save, quit Gedit, type "exit" in the Terminal window, close other apps, and reboot. Later you can change the Preferences in the Terminal program so that you can cut-and-paste shell commands from web pages like this, But I figure you want to get up-and-running right now, and will tinker with other configurations as needed later. Cheers!