Facility managers and safety professionals need immediate recognition and notification of a gunshot.
Relying on victims or bystanders to notify authorities can take too much precious time. Reliability and volume of information about the event location can change rapidly from initial incoming 911 calls to when law enforcement arrives on scene.
Dr. Bob Banerjee, of Nice Systems. posed the idea of using an IP camera enabled with audio detection capability and a powered microphone to detect a gunshot. click here for Dr. Bob's video
We hit the road to prove the concept at a shooting range in Virginia.
Objectives
Place cameras with the ability to receive an audio signal in an area where gun shots may occur.
Reliably detect a gunshot as compared to talking or yelling in the area.
Detect a gunshot close to the camera.
Ignore a gunshot further away from the camera. Ignoring a gunshot further away allows the proper camera(s) to create an audio alarm notification and direct authorities to the proper area in real time as the event unfolds quickly and from geographic area to geographic area in a building or on a campus.
Test equipment
Four Bosch cameras
Four powered microphones of various design
Laptop with web browser interface to cameras
Various guns from 9mm handgun to a .223 Remington rifle
Cinder block wall between gun ranges
Gunshots from adjacent gun range
Setup
Microphones of different types by Crown, Louroe, and other manufacturers were connected to amplifiers which were connected to the Bosch cameras’ line level audio inputs. The microphones were spread around the range which was approximately 25 meters x 25 meters in size.
Most models of Bosch Security Systems IP cameras have the ability to evaluate an incoming line level audio signal based on volume and frequency. This is not an add-on and does not cost anything additional to the base price of the camera.
For this test, we captured the audio alarm differences between same-room gunshots and distant-room gun shots.
The diagram below shows the test screens of the four cameras and microphones. There were four cameras, each with one microphone. The top of the image shows the specific test being conducted.
The image below depicts the frequencies that are monitored by the Bosch cameras:
Below is a screenshot of a 9mm handgun audio detection alarm using four Bosch IP cameras each equipped with powered microphone:
Below is the video of the data collected while testing of a variety of weapon types:
Technology application
The ability to detect a specific frequency at a specific volume is only half of the process. Once the “alarm state” is recognized by the camera, the next steps need to take place. The camera must be connected to another system to cause a notification to occur:
Email from the camera with snapshot attached sent to supervisors or staff
Alarm sent to video management system for camera call-up
Relay out of camera to send alarm over a wire to a monitored alarm system
Integration of systems to initiate a lockdown or evacuation
Integration of systems to initiate mass notification of instructions
