Audio suddenly stopped working

I'm running a Mac Pro on Mountain Lion, version 10.8.5. I installed the latest updates last night and the audio on my computer stopped working. None of the wires had been moved, and I tried unplugging and replugging them in, both to the back of the computer and to the headphone jack. I also tried plugging headphones into both, and there were no changes.

I have since tried rebooting my computer several times, I tried repairing permissions, I tried to use time machine to go back to before I updated the computer and I deleted the bezelservices preference file. None worked.

System preferences does not show the line out as an option under sound, and tells me that there are no options. Any suggestions welcome. Please help. Thank you in advance!