Before flying out of the starting blocks—and ultimately taking Olympic gold in the 100-meter race for the third time—Jamaica's Usain Bolt was met not with the fire of a pistol but a noise triggered by an electronic gun. Did previous Games use actual pistols?
Yes, but they've been scrapped for both safety and fairness. The guns were obviously firing blanks and were often rigged to blow off a puff of smoke so everyone could see. Some of the guns were even sealed shut and would just make a loud bang. In an interview with BBC Radio's "The Now Show," Alan Bell, the official Olympics starter at the 2012 Summer Games in London, said that he had even used a pistol with bullets stuffed with toilet paper.
In fact, the actual pistols used to start races have gotten some flak in recent years. One famous model, the Bruni Olympic .380 BBM, was banned in 2010 because it could be converted to fire live ammunition (other pistols that fire blanks must be brightly colored to avoid any confusion). Traveling with the guns—and the firing supplies—can also be a hassle in airports. And Bell himself was even banned from bringing a starting pistol to a race at a local school, leaving him to use a loud horn instead.
Enter OMEGA electronic start system: the plastic device doesn't fire at all, but triggers speakers behind each runner. It's also connected to the official timers and can't start without approval by the judges.
But the bigger issue the new electronic guns have solved is one of fairness, due to problems caused by the speed of sound. Runners in the lane farthest from the pistol were shown to have slower reaction times than those closest to it. Even wiring the starting blocks with speakers didn't help, since runners were still waiting for the pistol sound. In an interview with The Atlantic, OMEGA Timing board member Peter Hürzeler said that U.S. runner Michael Johnson's reaction time was as high as 440 thousandths of a second in the ninth lane, versus the normal 130 to 140 thousandth of a second, due to the lag time in hearing the sound. New Scientist also rounded up research on starting before the 2008 games and found that everything from location to the loudness of the pistol could affect the race.