Video Plus Audio Equals Enhanced Security

Extend the reach and response of surveillance cameras with sound capabilities.

By Geoffrey Bauer
From the August 2018 Issue

Today’s video surveillance systems have more intelligence and capabilities than ever before. Security cameras offer a range of features to protect property and deter crime with the application of analytics such as motion detection, face recognition, and license plate capture. And with the high resolution many cameras provide, it is now possible to view video with a level of detail unthinkable just a few years ago.


While higher resolutions traditionally translate into greater bandwidth and storage requirements—and the greater costs associated with each—advancements in video compression and recording solutions have lowered the barrier of entry for high-resolution video, making it more attainable for organizations of all sizes.

While video has proven invaluable for security, the more senses that a security system can engage, the more effective it can be. Consider that humans have five senses, each of which fills an important need. Obviously, touch, taste, and smell cannot be engaged remotely, but hearing can. Adding audio to augment video surveillance can enhance security coverage beyond the camera views to help detect and interpret events as they occur. It can also enable two-way communication over an IP network. As an added benefit, audio data can be transferred using the wired or wireless network that transfers video, improving system-wide distribution and deployment options, making integration of audio and video much easier.

Note: The use of audio can be restricted in some municipalities, states, or countries, so it is necessary to check with local authorities before deploying any audio solution.

There are many potential security and non-security applications for audio, including targeted retail messaging, aggression detection, monitoring high-traffic areas for safety, improving loss prevention, delivering remote help desk assistance, and background music services. Below are four key benefits of integrating audio with video surveillance to deliver enhanced security.

Deterrence. For perimeter access and other areas where facilities would normally install a camera, audio can now be added to the security. If a trigger occurs—such as a threshold crossed or a certain area breached, the system can automatically notify the command and control center of a potential event. Using two-way communication, an operator can interact with the area of concern, eliminating the need to deploy resources to handle the situation in person. For example, if an intruder were detected in a store after hours, rather than dispatch security personnel to investigate, an operator could speak directly to the individual(s) and issue a warning that they have been detected and recorded on video, and that police have been dispatched.

This live interaction can be further emphasized by using specific details about the intruder(s) physical characteristics to reinforce that the store is actively monitoring the premises. An alternative to live interaction, a security solution can utilize prerecorded messages to play when an alert is triggered. Different messages and message sequence can be varied to give the appearance of live monitoring. Both methods have proven effective in deterring crime, as intruders tend to exit quickly once they hear a voice.

Detection. In addition to enabling remote communication, audio can also be a proactive detection tool. Where at one time this may have meant a security operator would have to monitor live feeds, advances in audio analytics have automated this function by listening for particular sounds and generating alarms to alert security staff when these sounds are heard. Integrating a microphone allows the security platform to detect glass breaking, gunshots, screams, aggression, noise above a specified decibel level, and other potential threats. Once an audio analytic is triggered, the combination of video and audio allow an operator or security personnel to assess the situation and determine what, if any, action may be required.

Verification. For many years, false or nuisance alarms have been a major challenge for security professionals and end-users alike. The ability to verify alarms visually prior to dispatching police did much to alleviate this problem to the point where, in many municipalities, visual verification became a requirement. Adding audio provides a secondary means of verification by allowing operators to both see and hear what is occurring.

To use the previous example of a retail store, when an alarm is generated from an analytic on the surveillance camera, the audio (microphone) can be used to verify the type of alarm, motion detection for example, to determine if the alarm is actionable, or a false alarm. Two-way audio further enhances this capability by providing a way to communicate directly with the premises to determine whether an authorized individual may have inadvertently triggered an alert or alarm.

Situational Awareness. In an emergency, situational awareness can mean the difference between life and death. With a surveillance camera, operators have eyes on a property and provide up-to-the-minute information to first responders to speed response.

Audio capability adds ears to those eyes to deliver even greater awareness and enhance detection of escalating threats. With audio, operators and security personnel may be able to hear what is happening, communicate with the victim to assess the situation, and prioritize response while also providing situational intelligence to first responders.

When it comes to integrating audio with video surveillance, evaluate current system and goals before deciding which type of audio solution is the best fit. A network camera or video encoder with an integrated audio functionality often provides a built-in microphone and/or mic-in/line-in jack. This provides more flexibility, offering the ability to use an outside microphone, connect to more than one microphone, or place the microphone a distance away from the camera. Speakers with a build-in amplifier can be connected directly to a network video product with audio support.

With advancements in image quality and analytics, video surveillance has become a powerful tool. While the use of audio in video surveillance systems has lagged behind in terms of adoption, the advent of IP audio expands the possibilities of streamlining security operations and emergency response. With the benefits these integrated systems deliver, it is clear that audio can be an equally critical component as video for elevating security and situational awareness.

surveillanceBauer is architecture and engineering program manager at Axis Communications, a global provider of intelligent security solutions. He also serves as the product manager for AXIS Design Studio and technical liaison for Axis design tools. Bauer’s industry designations include ASIS International Physical Security Professional (PSP), BICSI Electronic Safety and Security Designer (ESS), Cisco Certified Entry Networking Technician (CCENT), Cisco Certified Network Associate Routing & Switching (CCNA), and Cisco Certified Design Associate (CCDA). He earned a B.S. in Electrical Engineering Technology from LeTourneau University.

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