Hi there. Might be a bit of an odd one, but I'm trying to research the plausibility of movie story line. During the 70s there used to be clunky old FM system hearing aids (Phonic Ear was a brand) that kids would strap the receiver to their chests and the teacher would wear the transmitter/microphone. Would it be plausible to track down the transmitter along the lines of transmitter hunting? Any help greatly appreciated!