There is a fascinating behavior I have seen amongst Americans and other communities around the world that are essentially monolingual. When they pick up on the fact that someone in their midst is speaking something other than their language they tend to do one of two things: 1) stare at the individual as if they had just emerged from a spaceship or 2) create as wide a girth as possible between themselves and the individual speaking – preferably snuggling in with others of their tongue if they are nearby. There is safety in numbers after all.
I can remember attending a university lecture once. The teacher and an assistant were both speaking Arabic prior to the lecture. Instead of the crowd of about 30 people coming in and filling up the seats as they normally would, everyone stayed outside until he finally peeked out the door wondering where they all were and told them all in English to come in.
In another incident, I myself was speaking Russian into a tape recorder in a living room in a home I was staying in. The English speakers could hear me in the other room and refused to enter despite my insistence that it wasn’t going to bother me if they were there eating lunch. They actually stood at the entrance whispering and tip toeing as if not to disturb a delicate operation taking place in their midst. Perhaps it was rude but I burst out laughing.
Whether it is out of awe and curiosity or ignorance and fear is a matter for each of you to decide. My experiences were specifically with crowds of English speakers, but I imagine the same effect would be possible amongst other groups as well. Either that or English speakers are just an anomaly (which is somewhat amusing when one considers that they typically consider themselves to be the top of every list imaginable – despite the fact they often disregard whether that list is a positive or negative one.)