It's been recently discovered that if you play AVP in another language the the sound in cutscenes no longer work. After investigating this, steam requires an additional language pack to be downloaded when you change languages (this is done automatically when you launch the game in another language). The game is able to do this naturally with the original FMV's and use the new language tracks to override the English version. For some reason this is not working with the 4K cutscenes. I'll look into it further to see if it's a simple patch. Until then, this package mod fully works in English.