Works in professional drag racing. Seems like it'd help prevent false starts in the sprints, especially since every start official has a different cadence before the start gun.
Granted, most sprinters are looking down at the ground while in the blocks and don't look up until 30m or so into the race. But even if there was a consistent pinging sound for each light on the "Christmas tree" (3 amber lights and then green, counting down 3 2 1 go) it seems like it would make the start smoother.