With security after the September 11 attacks on the US becoming prevalent and causing issues with starting pistols , a trend developed to use electronic starting systems that do not use pistols but use a " dummy " prop pistol which can not function as a firearm and that is wired to the timing system . When the starter presses the button , they emit a signal to play a simulated gunshot that is broadcast to loudspeakers behind each lane , show a flash , emit simulated smoke , and start the timing clock . Many venues have switched to the new format . Beyond the security concerns , it has also been observed that even with the use of loudspeakers , some competitors still wait for the actual sound of the gun to reach them , and since the new all-electronic starting pistols have no such problems , they became the official way of starting games at the 2012 Summer Olympics
September 11 attacks
September 11 attacks
Starting pistol