No sound with external monitor Windows 10

[wzukowski]

Have no sound with external monitor connected through HDMI port (Win 10). The speaker icon does not show 'Playback devices', when selected through start menu, the Sound menu does not list HDMI.

 

[Peter Martin]

based on the amount of detail and lack of specs, have a gander at this
https://support.microsoft.com/en-us/help/4026994/windows-fix-sound-problems#v1h=tab01