Fallout Sound issue

Alright, so every single fallout game I play, 3, new vegas, and fallout 4 all have the same issue.
Whenever I'm speaking to another character their mouths move but there's no audio coming from them. No fallout game has any dialogue audio.
Skyrim works fine, any other game in my library has no problems either, just fallout.
When I plug my HDMI cable into my TV and play the game through there the audio works fine for fallout. But if it's plugged into my monitor and my sound is coming through speakers or headphones theres no dialogue. (also, all other noises within the game work. gun fire/explosions, NPCs talking in the distance)
Any ideas?

 

let me get this straight, you aren't getting any dialogue audio in Fallout
but all the other ambient sounds are working correctly? if so, the first
thing you should do is check your installation, it sounds like the game is
unable to pick up the audio files to go along with the dialogue.

If you are running steam you can check the game cache integrity through
the steam platform. More information on how to do so here:
https://support.steampowered.com/kb_article.php?ref=2037-QEUH-3335

If you downloaded the game I suggest you locate your save files and try
importing them on a different installation. or maybe even see if you can
find the correct dialogue audio files and place them in the correct directories.

 

Sounds like a game file problem or a driver issue, though I'd be surprised if it were a driver issue considering Skyrim and FO4 use the exact same engine just that FO4 has been tweaked for next gen. Regardless it might be worth a look. Search for your motherboard/sound card manufacturer and visit their support site to download new drivers.