AVID - Audio Troubleshooting Can't Hear Audio Playback CMB 4.112 and CMB 4.120

Go to >Apple > System Settings

Once you have your AVID Project Open
Check the Hardware I/O button and make sure the UltraStudio 4K is selected

The next step is to activate it

If it already has a RED Arrow, then it is Active
If not, then press this icon once.

When the TV Icon has a RED Arrow
AVID should be passing through the audio and video to The TV and Headphone Amp

If you still don't hear audio the check your AVID Project Preferences sometimes toggling to a HD setting helps

Go to >Avid Media Composer>Preferences