Hey! I just solved this issue with the help of the VB forums. (I'm assuming you're running the Gnome version of LM 9, I am)
Open gedit (OpenOffice won't work, I don't know why) and copy/paste the following three lines into it.
options snd-intel8x0 ac97_clock=48000
options snd slots=snd-intel8x0
alias snd-card-0 snd-intel8x0
Save the file as "sound". Find the file (in documents or wherever you saved it) and change the name to "sound.conf"
Type alt+F2. In the window that pops up type in "gksudo nautilus" then hit return. Type in your password.
Now you should be in a red File Browser. (that means you have root privilege) Now move the sound.conf file into File System/etc/modprobe.d
This should solve your issue. (You may have to log out and back in or restart LM 9)