Listen Up!
A technology being used in Chicago recognizes the sound of a gunshot within a two-block radius, pinpoints the source, turns a surveillance camera toward the shooter and places a 9-1-1 call.
The video surveillance system, part of a pilot project, helped to reduce Chicago’s murder rate to its lowest level in four decades. The Safety Dynamics system — known formally as Smart Sensor Enabled Neural Threat Recognition and Identification or SENTRI — uses four microphones to pinpoint the shooter.
An interface directs a camera in the direction of the gunshot and sends an audible and visible alarm to the city’s 9-1-1 center. Inside the 9-1-1 center, retired Chicago police officers monitor the cameras 24 hours a day.
“They use zone radios to connect to the necessary departments,” says Greg Hoffman, Chicago police department sergeant. “Our primary focus is to disrupt activity in areas with high narcotic gang and firearm-related violence.”
The technology is employed in about one-third of Chicago’s 53 cameras.
“Our goal is to prevent homicides from happening, and we are hoping by increasing our surveillance we can get that message out,” says David Bayless, Chicago police department director of news affairs.
SENTRI, developed by Safety Dynamics, Oakbrook, Ill., uses Dynamic Synapse Neural Network (DSNN) technology developed by Dr. Theodore Berger, David Packard professor of engineering and director of the Center for Neural Engineering at the University of Southern California. DSNN can recognize sound signatures as short as a gunshot or as long and varied as a diesel truck. It is designed to recognize a sound signature using multiple points and patterns of reference.
In Los Angeles County, the sheriff’s department plans to deploy 20 units in a pilot test.
“We hope to install it later this year, says Ramiro Juarez, deputy for the Los Angeles County sheriff department. “If it works, it would help us know what’s happening in our district. Recently the city used a different system that plotted an acoustic event on a digital map. It broke around three years ago.”
“We needed to gain technological advantage over the area,” says Sid Heal, commander for the Los Angeles County Sheriff Department. “Our previous system had dramatic impact. It was installed on New Year’s Eve in 1999, and it recorded 1,100 gun shot incidents in the first 60 minutes. It pinpointed that 25 percent of the gunshots were coming from one house.”
The pilot system to be implemented by the Los Angeles Sheriff’s Department, SENTRI II, is manufactured and distributed by Sound & Optics Systems, and it uses the Smart Sensor Enabled Neural Threat Recognition and Identification (SENTRI) acoustic recognition system developed by Safety Dynamics. The SENTRI II is a platform that integrates sensory technology, cameras and communication systems to efficiently detect and report specific stimuli. After identifying stimuli, it then directs a camera to the source, within a fraction of a second. System sensors detect stimuli based on intelligent neural-based rules to: pinpoint the location of the stimuli; pan the camera to the stimuli location; send the alarm (audible and visual) to the Control Center; send real-time images and audio to the Control Center; and activate the system strobe light or beacon.
“The system will detect weapons fire and give officers in the Command Center a view of the action within seconds,” says Mike Andrews, senior vice president for Sound & Optics Systems. “This allows a more informed response, increases officer safety and provides an accurate account of the situation.”
Officials in Tijuana, Mexico, recently bought 353 units. Police in San Diego and San Francisco will soon launch a test program, and New Orleans and Atlanta also have made inquiries. Safety Dynamics also works with the U.S. Army and Navy to develop systems to detect a range of sounds such as glass shattering or diesel trucks slowing in an unexpected location. Additional applications being explored with potential customers include: pipeline security, facilities and perimeter monitoring and protection of natural resources.