Like one of the previous posters said, this worked for me to fix the strangely delayed sounds but it introduced a new problem. Now I stutter horribly when I am around NPC's (didn't do this before the sound was fixed) so I'm at a loss for words. *shrug*
There is a solution for that. Pop their heads off. Literally. It works for some, disabling emotions works a little bit also.
http://www.gamesas.com/index.php?/topic/1123107-fps-drop-when-near-npcs/
These two I am looking forward to trying. A headless New Vegas awaits me when I get off work in a hour and half, lmao!

@ KyleM - Trust me, uninstalling was a big pain for me. My steam bugged out and it took me 3 hours to get it and New Vegas back. Be very afraid of the uninstall