Due to old OpenAL libraries, there is no sound. In order to fix that, the OpenAL DLL needs to be replaced with up-to-date copy.

No sound on launch; this can be fixed by updating OpenAL DLLs. In order to do so, download up-to-date Windows build from OpenAL Soft website, then unzip the 64-bit version of the DLL (under bin/Win64 directory), and replace OpenAL32.dll in game directory with the new one.

If you have protontricks installed, you can run the following snippet to have it done automatically:

curl -o openal.zip "https://openal-soft.org/openal-binaries/openal-soft-1.20.1-bin.zip" &&
unzip -jd . openal.zip openal-soft-1.20.1-bin/bin/Win64/soft_oal.dll &&
mv soft_oal.dll "$(protontricks -c 'echo $PWD' 973020)/OpenAL32.dll" &&
rm openal.zip