Adjusting alert preferences for messages, mentions, and activity within Teams Free
The best first option is to go to the support page for your PC on the manufacturers website, then from there, download and manually reinstall the HD Audio drivers, you also need to manually re-install the Graphics drivers, because they provide the audio drivers used by the HDMI connection on a monitor.
If you are still unable to get audio through the HDMI connection, on the back of your monitor is a label, what is the make and model number of your monitor?