Two individuals are standing in your parking garage. The video feed shows erratic body language and an animated verbal exchange.
Wouldn’t it be nice to know if the two are enthusiastically discussing the latest sports event or if this heated conversation is a sign of escalating aggression? Without audio, your best guess is based on watching a silent movie.
The ability to hear can make a world of difference to your security response. There’s a distinct advantage when you can use live audio to detect suspicious activity, validate threats and neutralize an unfolding situation. Learn about three options that will put eyes in the sky and ears on the ground: cameras with microphones, video intercoms and audio analytics.
An Audible Benefit
The human ear has an amazing capacity to sense danger, assessing tone, pitch, words and distinct sounds to instantly assess their threat level. Audio surveillance enables security operators to use two of their five senses rather than just one for an instantaneous increase in situational awareness. They don’t have to be present in an area to hear suspicious activity any more than they have to be in the same location to see it.
“Audio surveillance augments the human capacity for security,” says Richard Brent, CEO of Louroe Electronics. “You can detect and respond to a situation more quickly. Live sound helps you take action and prevent rather than react to threats.”
From a budget standpoint, adding audio is minimal. Newer cameras may already have built-in microphones that are simple to activate with a click of a mouse. Even your legacy cameras are likely to have an audio jack that connects to a microphone cable. If you want to automate sound detection, there are also a growing number of companies that offer analytics as part of their package.
When discussing audio’s value proposition with your leadership, frame it as avoided costs, recommends Brent. What’s it worth to your organization to prevent one altercation from going further than it should? The financial repercussions of compromised security can range from property destruction and theft to more serious instances of legal liability if people are injured. The combination of video and audio puts additional data into the hands of your security team so they can assess and respond with speed.
Aside from sensitive areas where the expectation of privacy is a given, such as restrooms and locker rooms, audio has no physical limitations in your building. You can use electronic ears in a host of external applications, from entrances and loading areas to parking lots and perimeter zones. Camera mics are equally as useful inside your facility, including lobbies, work areas, classrooms, corridors, stairwells, cafeterias and gyms. Anywhere you have a security camera can be optimized with sound as well.
One caveat is how much background noise is present. For example, traffic noise may interfere with audio quality if your property is near a busy road. An open work area with echoes or a factory with loud equipment could impede sound recognition in a similar manner. An apt example where audio‘s effectiveness is rendered mute – a sports venue. A place where people normally cheer, scream and yell will make it hard to detect legitimate aggression from enthusiastic fan behavior, says Brent.
No matter where you want to place audio, first determine what you want to hear (see sidebar below). Is it a matter of listening in real time when warranted or letting software determine when an unusual sound has occurred? This seems like a simple question, but the answer will dictate what type of listening technology you need.
The Right Equipment
While sourcing audio equipment is relatively straightforward, pay close attention to its installation. Microphone placement is different than field of view. The best place for a camera is usually in the corner of a room and high out of reach, but sound isn’t contained at the edges of a space, Brent notes. Unless you have a sophisticated audio capture device that can pick up sounds from the middle of the room, the audio could be garbled, distorted or out of sync with the video. In these cases, you can run the cabling for a plug-in microphone behind the walls or ceiling so you can place the mic in an effective location separate from the camera.
Also consider that all microphones are not created equal. For example, a mic used by a singer is designed to capture a different set of audio frequencies than the sounds needed beyond the human ear for surveillance purposes, says Brent. A poor quality microphone is about as useful as a poor quality camera. Depending on what you want to register, you may need more advanced microphones that have a high sensitivity and can filter out ambient noise, suggests Steve Surfaro, Industry Liaison for Axis Communications.
But don’t forget about the camera itself – the video is the foundation for audio. To achieve the right balance of visual and audio acuity, you need a strong resolution to have clear footage and the right audio capabilities to process cascading sounds, Surfaro explains. Owners with CCTV or a mix of analog and IP equipment will have to work around their existing systems to achieve useable audio. If your video is for general observation, a full system upgrade may not be required – microphones will be able to distinguish classes of objects in the field of view, recommends Surfaro. If you want to isolate individual sounds, however, installing HDTV cameras with quality microphones can aid in forensic investigations.
Another functionality you may want to secure is two-way communication. Not only will you be able to listen to an area, but you can deliver live messages using the same speaker equipment, Surfaro says. In a crisis, voice communication can deliver instructions or reassurance to occupants as you keep visual and audio tabs on the situation. If an individual is detected committing violence or vandalism, you can tell them to cease and desist and that security is responding to their location.