Surveillance has long been about video, with CCTV surveillance cameras dominating the scene. But with the advent of many modern technologies and security cameras, we are also seeing audio come into play, as evidenced by the growing use of audio analytics in securing businesses and public areas. Video is an excellent way to keep a literal eye on a property, especially when combined with video analytics – a major innovation in security we’re all familiar with. But audio brings another level of detection and accuracy that can greatly enhance security efforts.
How Do Audio Analytics Work?
Audio analytics start with microphones placed around the area under surveillance, whether standalone or integrate into a surveillance camera. Using the audio these microphones pick up, the audio analytic software is capable of detecting everything from pitch to decibel level on many different frequencies, sorting them and using special algorithms to detect and recognize various sounds, such as gunshots, breaking glass, and verbal aggression. There is, of course, a lot of sound being thrown around the background, which is why they are also programmed to ignore everyday sounds such as crowds, cars and background music.
Properly detecting and recognizing audio signals requires a high level of sensitivity and sophistication, to be able to discern the sound from background noise as well as avoid false positives.
What Can Audio Analytics Do?
Automatic audio detection gives the option of many features that offer enhanced security over traditional video and security systems. When certain flagged noises, such as breaking glass, are detected, the system can be setup to alert either monitoring station or on-duty security personnel for immediate response, or in-home use, simply alert homeowners and users via their preferred device. It can also immediately live-stream video footage to the monitoring station or similar for quick, on-the-spot surveillance.
Of course, thanks to the rapid and constant advances in machine learning, the number of detectable sounds is always expanding, and audio analytics programs can now be programmed to recognize and flag virtually any distinct sound.
Do Cameras and Microphones Record Audio All The Time?
Unlike traditional video cameras and microphones, the microphones on security cameras generally do not record audio all the time. Instead, it records only a few seconds of audio before and after the detected audio signal for analyzing and keeping as a record. Without storing more than a few clips of a few seconds per clip, this eliminates the need for massive storage capacity and keeps the system running quickly and smoothly.
Where Does Audio Processing Take Place?
In most cases, audio processing and analytics are hosted within the camera or audio device itself, which can help eliminate the need for a central server in certain situations – saving time, money and maintenance.
Why Are Audio Analytics Important?
Video surveillance has traditionally done an excellent job at providing a first line of defense, especially when coupled with newer video analytics. But with security’s everchanging landscape, the need for audio analytics has come to the forefront. Audio can often be the first sign of an incident or break-in, long before any visual clues pop up. And while full property coverage is important, there are often situations where it is simply not possible to cover every single window, corner and angle in the building, making audio detection and the ability to recognize certain sounds (such as broken glass, a car alarm, or even gunshots) essential to achieving proper security coverage. In such cases, audio analytics and corresponding alerts become the first line of defense, allowing security personnel to respond quickly and on target.
Furthermore, audio detection can trigger video recording – on one camera – or across an entire system, when loud or flagged noises are picked up, in the same manner that video analytics often starts video recording. If surveillance cameras do always not need to be recording, businesses can save thousands on storage for their CCTV systems.
