One of the reasons why I don't wear regular earphones is so that the person sitting next to me wouldn't be annoyed if I decide to play my music a little louder than usual. Similarly, I also want to isolate external noise as much as I can to fully appreciate the art that goes behind the production of music, because even if the volume is really high, external noise still gets in when regular earphones are used.
That said, if you're not wearing noise-cancelling headphones or noise-isolating earphones (proper terms for each), you cannot pretend like you can't hear people calling your name within close proximity, probably at just about 12 inches away from your ear (regular ruler's length).
Now, should you decide to continue with your juvenile ways, I suggest you fund your act accordingly by acquiring the necessary props. Otherwise, you risk being perceived as a brat or a fool. Up to you.