SP&T News

News Camera Corner Opinion
Eyes and ears in security

Surveillance coupled with audio technology has advantages, but is anyone listening?

April 13, 2021  By  Colin Bodbyl

Remote audio has become a critical part of everyday life. From car radios to cell phone conversations, our lives would be very different without the ability to transmit and record audio from remote locations. But the technology has never gained popularity in the video surveillance industry. Some end users may not even realize their video surveillance system has the ability to support audio technology. Yet leveraging the functionality can add great value to the complete solution.

There are three different methods in which audio can be deployed in combination with video surveillance. One-way inbound audio is what most people imagine when we talk about video surveillance with audio.

This is done using a microphone to record the audio from the area surrounding the camera. The microphone required to offer this service can be very small and is often built into the camera. Recording audio without the consent of those being recorded is illegal in some areas. The variety of laws that differ by region, along with the fact that many of them are unclear, has prevented audio recording from ever becoming a standard feature. Where laws permit, audio recording in combination with video surveillance is most commonly deployed in courts, police stations and prisons. One-way outbound audio is the opposite solution. With outbound audio, the camera is used to project audio that can be heard in the area the camera is located.

This typically requires an external speaker that is not supplied or built into the camera, although the camera itself will need to have an audio output to support the speaker. Outbound audio can be particularly useful as a tool for deterring criminals.


It can also be used as an operational tool, for transmitting messages from a remote location. Some examples include warning workers of potential safety violations or alerting tenants of a building to vacate a particular area that is closing for the night. The risks and liabilities associated with outbound audio are minimal, though operators could find themselves the target of noise complaints if the technology is not used responsibly.

Two-way audio is of course the combination of the above two solutions. This is often better accomplished through an intercom, but is technically possible through a camera. For effective two-way communication, installers will likely need to use both an external microphone and speaker strategically positioned for best performance. Another challenge for two-way audio can be routing these conversations through the video management software. This can be especially difficult in situations where multiple two-way audio locations exist, or multiple operators are using the same soft-ware. This complexity is partially what has prevented video systems from becoming a tool for managing two-way audio, since purpose-built intercom systems are far superior at scale.

Audio solutions deployed using any of these three methods remains rare in the video surveillance industry. Manufacturers have removed many of the technical and cost barriers that once existed by including free audio support on cam-eras and in video management software. Unfortunately, the lack of clear or consistent regulation creates hesitancy amongst integrators who choose not to promote the technology. In the consumer market, big box manufacturers have been far less careful, with video doorbells being a clear example of a product that both records and transmits audio with little concern for legal barriers. This could either open doors for the security industry to leverage audio more frequently in similar applications or could drive regulators to clarify the laws with more specific terminology.

Either way it brings attention to a widely available, though severely underutilized, security product. The surveillance industry will be watching closely what happens with consumer products, but for the near future it is likely that audio on video surveillance systems will remain a niche product.

Colin Bodbyl is the chief technology officer of Stealth Monitoring (www.stealthmonitoring.com)

Print this page


Stories continue below