A lot of runs I have seen on Glitchless are playing the game with Italian audio and English text. How Do I do this? Playing on Steam by the way.

You gotta go into properties -> language and choose italian. Then you go into the data folder in your fnv steam folder and put the voices1.bsa file somewhere else. Go back to properties and set the language to english, after that put the voices1.bsa file from earlier into data folder and overwrite. Or download the voices1 file from here: https://drive.google.com/open?id=0B7PgQA0MiY-sNkVtVElfVVZZajg