That used to happen to me in school. I'd be bored enough to actually turn to socializing for some stimulation, and I'd be totally ignored. One day, I took a chance and tried testing to see if they could hear me by calling them idiots and saying I hate them. Not one iota of a response. I tried saying it a little louder, and there was still no response. I was too disturbed to even be offended; it felt like I was stuck in some alternate reality where I was invisible or something!
_________________
I'm female; my username is a pun on "nickname."