no audio from DisplayPort

Currently running Slackware64 14.2 and everything was great until I upgraded my video card to an EVGA nVidia GTX 780. I’m also using the NVIDIA-Linux-x86_64-367.44 drivers, which also worked fine with the old card. this new card still has the DisplayPort output, which I’m using with the same monitor setup that worked fine on the previous nVidia GPU. With this new video card there is no audio coming out from the DisplayPort so I’m hoping I’m just missing something. I know the monitor, cables, and speakers are fine since they worked with the old video card and just to make sure I plugged in a Chromecast and that worked as well. I know the video card itself works because I was able to get sound out via the DisplayPort in Windows, so everything works hardware wise. In Linux the sound system involved is pulseaudio and all my sound outputs work fine except for the HDMI/DisplayPort. any suggestions?