Hey Hrsut32!
Sorry to see you're experiencing this.
To look into this further, could you please attempt the following workaround?
1.Go to Far Cry 5 in your Steam library, right-click the game and select Properties
2. Click on the Languages tab, select any other language than the one you wish to use in the drop down menu. Example, switching from Russian to German.
3. Start the game and click the first option on the menu screen as this is usually the Continue button. Allow the scene to play.
4. If you have voices again, close the game and do step 1 and 2 to re-select your desired language.
5. Start the game, click 'continue' and wait again for a specific scene that had no audio and check if you now can hear the voice of the characters, in your desired language.
Please let us know if this issue persists after that