Is the HDMI cable plugged in?
If so remove it.
No sorry I didn't have anything plugged into it besides the dvi adapter.
I was able to get the sound back somehow but it was barely audible and sounded like it was coming out of a tin can so I bought a cheap sound card. Problem solved! Unfortunately not the way I wanted to solve it but I was at a loss to find a proper solution. Thanks for your help though!