Even legitimate buyers on GOG, Steam, or EA App have reported that during the download or installation process, the English localization files fail to unpack correctly. This leaves the player with a silent Psycho or a UI that mixes English menus with Polish subtitles.
The audio codec mismatch. The English pack expects MP3 or OGG Vorbis, but your game engine is looking for ADPCM (used in Russian builds). Fix: Delete the Shaders.pak and ShadersCache.pak in the root Game folder. The game will rebuild them on launch, realigning with the English audio files. Crysis Warhead English Language Pack