I also had that issue of the missing Sound, after the Intro.
What fixed it for me was downloading the June2010 Directx Redist from Microsoft and install/reinstall it.
Just Download it, run the installer to extract the files to a folder of youre choice. After that run the Setup in said folder, and let the DirectX Installer do its work.
I cant link it, because links are not allowed, but just google for “directx june2010 redist”, and the first search result should be the correct one.
This is what fixed it for me atleast. Hope it helps!