Q: No Sound Asus MX279 Monitor hooked up to MacBook Pro

Just purchased an Asus MX279H monitor to connect to my 2012 MacBook Pro (OS 10.9.4).  I'm using a 10ft DisplayPort to HDMI cable from CableMatters.  Picture display is working great, but I cannot get the sound from the monitor speakers to function.  The audio output cable to headphone jack doesn't work either.  I've even tried to configure the audio device via the Audio MIDI utility on the MacbookPro.  I can test the monitor speakers via this utility on the computer, but still cannot get the computer output to communicate with the speakers.  Is it the cable? Or something else?  I thought a cable would be a better option than using the VGA to DisplayPort Adapter.  Maybe I'm wrong?

Thanks for any suggestions!