I can definitely relate to hearing “hello” or “hi” behind you. When I first started getting my EDS it got to the point where two or three times a week I would be walking down the hallway at school and hear people calling my name when no one I knew was anywhere to be seen.
I’ve even had the random websites thing happen. A few times I have actually woken up in the middle of the night, and started to type on my bed as I went to the websites and checked them out randomly. None of them actually being real sites though, I even tried to go to a few the next morning just for kicks.
Pretty much all of my hallucinations are auditory. Except for the occasional spider one, but luckily I haven’t had one of those for a long time. Being arachnophobia and hallucinating about spiders aren’t very pleasant things to mix together.