sentences:  Children would gather in the area to collect coins after a caller left, often to buy candy at the store across the road.Operation required using actual coins, and lengthy long-distance calls with mid-call collect signals required deft manipulation of the noisy coins falling to the return, usually by covering the microphone with the hand or simply turning one's back to the phone.More recent research (2001) on a Flowbox by "Flame0ut & PrussianSnow" on Nortel Millennium payphones in Canada indicate that the Collect signal on many systems is a current reversal.