Android smartphone app triangulates gunfire

We recently wrote about Vaporsens, the handheld electronic dog’s nose that can help police forces accurately determine the presence of illegal substances. Now, researchers at the Vanderbilt University in Nashville have developed a smartphone app that can detect the origin of gunfire. Gunshots have a unique sound that can be separated out from ambient noise due to the fact that the majority produce a “muzzle blast – an expanding balloon of sound that spreads out from the muzzle each time the rifle is fired”, followed by the “distinctive shockwaves” created by traveling bullets, the team explain. The app is combined with an external sensor module, which contains multiple high-sensitivity microphones that can detect when a gunshot is fired. Using triangulation based on the differing times the soundwaves hit each microphone, the device then sends information about the direction and distance of the shot to the smartphone via Bluetooth, overlayed onto a map of the location. The system currently takes the form of two versions; one which uses only one microphone module that provides a rough estimate of the location, and another which relies on six separate modules, which could be placed on the persons of separate officers, to provide an accurate location of the shooter. The app could help police forces, soldiers or even civilians by providing them with greater information when under attack, potentially saving lives. Could the technology be modified to detect the location of other types of soundwaves – such as explosions to help firefighters locate the cause of a blaze, or the epicenter of an earthquake to help emergency responders?