Some versions of the Fallout Trilogy are missing two files from the Fallout Tactics/Core folder. If you are no hearing all the sound effects, you can download the missing files here:

http://www.gamesas.com/downloads/fot_sounds.zip

Unzip the file, copy the two resulting files (sound_0.bos & sound_amb.bos) to your Fallout Tactics/Core folder. You only need these files if they are missing from your installed folder.