Given the information it's difficult to understand what the real problem is. I don't think it's an audio issue unless whatever you needed to install was installed incorrectly. Make sure you have Directx11 as the game requires that. Also it would be helpful if you share your PC specs.
Processor: Intel(R) Core(TM) i5-3570 CPU @ 3.40GHz (3.40 GHz)
Installed RAM: 16.0 GB
Device ID: 40575A8B-4764-4871-BE67-5B2919F86FB3
Product ID: 00331-10000-00001-AA852
System type: 64-bit operating system, x64-based processor
I don't really understand much so I just sent you the main stuff(I think) let me know if this helps with the problem or I just did something wrong
Good news I sorted it I just had to reinstall the game and directX and it's working now😋
Im 94% though the demo I just don't know if there are more endings other than the ambush and I'm struggling on getting the endings since I think I should have the demo locked one but it says I don't but sorry for bothering you the game is fun😋