Chances are, you'll confuse at least 10 household sounds with your frogs before you actually hear them calling..... pretty sure this happened to just about everyone on the way into the hobby.
*AC UNIT* Oh man, I just heard this weird sound.
*CELING FAN* Dude, do you hear that creaking noise behind the usual fan sound?
*DOG BARKS OUTSIDE* My frogs are totally calling.
*TV'S ON* No way those were crickets man, my frog's totally calling now.
*LEUC CALLS* Oh, so that's what it sounds like. Hell yes, that's really cool.
*TINC CALLS* My tinc's vibrating, but I don't hear anything. *opens tank lid, hears quiet buzzing* Oh.