in the american fight against gun crime? you can tell a lot from a waveform. how loud, how high, what frequency. train a computer algorithm and it can, in theory, work out what it might be listening to. the's the idea behind shotspotter — that a computer can detect a gunshot and then tell the police the location it was fired from. gun fire. small mics are placed around a neighbourhood. when a gunshot is fired the mics pick up the sound, how long it took to reach the sensors and from which direction, effectively triangulating the shot.