This guide explains what the .dat and .fat files are in Far Cry 3 , specifically regarding the soundenglish (or other language) archives, and how to modify or extract them.

Without both files working in perfect synchronization, the game cannot "read" the audio, resulting in a silent experience or a crash to desktop. Common Issues and Why They Happen

To access individual sounds, you must "unpack" these archives. Tools like Gibbed's Dunia 2 Tools are standard for this; you simply drag the .fat file onto the unpack.exe utility.