Cause: You only installed the text pack, not the sound pack.
Fix: Verify that Sounds_English.pak (or similar) exists inside \Game\Localized\English\. If not, download a full pack (500MB+).
Unlike modern games that let you change audio with a dropdown menu, older CryEngine 2 titles often hard-locked language files during installation. There are three specific scenarios where downloading an English language pack is the only solution: Crysis 1 English Language Pack Download
If you tell me which platform you use (Steam, GOG, retail, or other) and whether you already tried verifying/repairing files, I’ll give platform-specific commands and exact folder paths to check. Cause: You only installed the text pack, not the sound pack
(Invoking related search suggestions now.) Crysis 1 English Language Pack Download