My biggest pet peeve

What really bothers me most about some people is when they whisper while I'm right next to them. Its not so much the paranoid feeling that they are talking about me its just how awkward of a feeling it gives too everyone in the conversation. This also goes for mumbling which i consider just as similar to whispering. An example is the other day when i was playing a 2 hour long board game (in which i deeply regretted) and the two girls sitting next to me wouldn't stop whispering. They were working together so they had to communicate with each other in some way but sitting next to them for 2 hours straight and hearing only the snake-like sounds of their voices come out drove me crazy pretty fast. Even when they were talking normally they mumbled the last half of all their sentences. This i just cant stand and i began to feel claustrophobic in a way that all i wanted to do was flip over the table and yell at them. I felt tremors coming on and sweating, just ready to break. I may be taking it to the extreme but mumbling and whispering is just too annoying to me.