Monitor's sound output missing from sound settings

I'm using a Thinkpad T480, and a Dell U3818DW monitor over USB-C.

In regular Ubuntu, I can select my monitor's built-in speakers as a sound output:


However in Ubuntu MATE, this output simply doesn't appear. It only shows the laptop's built-in speakers.

Google has not helped.

Any suggestions?

Try installing PulseAudio Volume Control (pavucontrol)

This is like a more detailed version of the built-in :speaker: Sound settings, but has a tab called Configuration where you might be able to find the hardware to enable/disable and ensure the correct profile is selected in the drop-down list.

If it's not listed, perhaps there's a package that needs installing to provide USB-C audio support.