BRAINS BEHIND GUNSHOT SPOTTER

Who knew? A few weeks back, we men­tioned that Chicago was set­ting up a series of lis­ten­ing posts, to keep an ear out for gun­shots. Well, it turns out that the sys­tem, called SENTRI, is based on the way peo­ples’ neu­rons fire.

SENTRI is an acronym for “Smart Sensor Enabled Neural Threat Recognition and Identification.” The “neural” in the title refers directly to [USC Center for Neural Engineering direc­tor Theodore] Berger’s work, which was based on analy­sis of the “lan­guage” nerve cells, or neu­rons, use to con­vey infor­ma­tion, and specif­i­cally on his mod­el­ing of the way the brain forms mem­o­ries of sounds.
The neu­rons’ only way of dis­tin­guish­ing sig­nals is to fire repeat­edly, either faster or slower, in dif­fer­ent tem­po­ral pat­terns. “It is the time dif­fer­ence between pulses that car­ries the infor­ma­tion,” Berger said. “This is a cod­ing com­pletely unlike that used by com­put­ers, which are col­lec­tions of ones and zeros, chang­ing to the beat of a con­stant clock.“
Working with com­puter spe­cial­ists, how­ever, Berger has cre­ated neural-​​like com­puter sys­tems that can model the neural time cod­ing and make dis­tinc­tions the way nerves do.
Four years ago, he and a col­league used the tech­nique to demon­strate the first speech recog­ni­tion sys­tem that could pick words out of ambi­ent noise as well as humans can. While work con­tin­ues on speech-​​recognition appli­ca­tions, the sys­tems need train­ing to learn indi­vid­ual sig­nals. For lan­guage, this is very time con­sum­ing because the sys­tem has to learn each indi­vid­ual word.
“But for alarm sig­nals,” Berger said, “you start with a rel­a­tively small num­ber of sounds you have to dis­tin­guish with high accu­racy — gun­shots, for exam­ple, or diesel engines for bor­der patrol cross­ings or oil pipeline thieves, or chain­saws to lis­ten for out­law log­gers. This vocab­u­lary is quite man­age­able.“
(thanks RC for the tip)

December 9th, 2004 | Guns | Comments Off Both comments and pings are currently closed.