New monitor to hdmi , sound not working

Hello, i recently purchased a new lg monitor and the sound isn't working on it. I have build in speakers on the monitor, and on the playback devices it says it playing sound but i hear nothing. I tried to used nvidia to fix the problem but nothing working atm any tips?

Hi welcome to the forum

could you post a screen shot of the default playback device page.
also could you list make and model of monitor