Hi there, there is sound when cinematics are happening but whenever actual gameplay starts, then you cannot hear anything. This happens onjly when PC is connected via HDMI and playing on TV.

Could anyone help me resolve this please?

Someone mentioned the same issue here:
https://steamcommunity.com/app/108710/discussions/0/492379439679877847/

He solved the problem by only using his tv. (You can chose to only enable the tv in your graphics card configuration panel instead of having it set up as a separate monitor or cloned display). Then, you switch it back after you're done playing to use your monitor again.

I also suggest checking your audio settings to make sure you set the digital audio / hdmi audio to default (although, that may vary depending on your audio drivers and programs installed with your audio drivers). I had a problem recently where I wasn't getting any sound through hdmi until I did that.

i had this problem with my sound and fixed it by unplugging the speaker out socket on the back of my pc that goes to my pc speakers

it was only a problem when i played my videos i had recorded from my pc's tv card onto the harddrive and tried to play them back using klite media player

hope that helps