I've searched for this and found a few other people with the same issue but I saw no solutions. I really hope someone can help solve it as the game is rendered pretty unplayable currently.
I have F:NV Ultimate Edition on steam, and any time I am looking in the direction of a neon sign or lamp, even from quite far away, there is an abominably loud constant buzzing noise. It's loud enough that I can't hear anything else and it's unbearable to listen to. I can be really near a light source and not hear buzzing if I turn away from it, but if I happen to be facing it's direction, I'm deafened even if I'm 2 floors down.
I do have electro city installed, but that doesn't seem to be the problem. Is this a known issue? Is there any mod that can fix it? I don't recall having any such problem with F:NV on the xbox, but it's crippling my PC playthrough.