is it possible to discern a frum person's voice?

i was sitting in the student lounge, waiting for class to resume after a test. (which, by the way, is the cruelest thing a professor can do to a class IMNSHO. after an exam, no one wants to look at the professor's face. they all just want him/her to go home and mark the tests) i was speculating on the exam, and trying to start studying for an exam which i have on chol hamoed. it was pretty deserted, and i was wondering if the heap of clothing in the corner was a forgotten pile or a person. suddenly, i heard a voice and footsteps coming up the stairs

"yo. what's up? where the heck have you been, man?"

the first thing that popped into my mind was that it belonged to a frum person. i couldn't put my finger on it, but somehow the voice had sounded so.....Jewish.

i peered around the corner, and sure enough, a yarmulke went barreling down the hall, talking at 80 mph.

it was so strange.