Hooray! I finally disabled sound altogether in Ubuntu! It was surprisingly difficult… but in the end all I did was copy the noALSA.modprobe.conf file to /etc/modprobe.d/:

cp /lib/linux-sound-base/noALSA.modprobe.conf /etc/modprobe.d/

Helpful Link:

http://ubuntuforums.org/showthread.php?p=1824685

¥