We Hear You

Intercoms necessary to order lockdowns, or evacuations

Granted, a picture may be worth a thousand words, but there are times it is vital also to hear what’s happening to best assess a situation or provide needed information. Law enforcement and security professionals routinely rely on audio technology to help keep people safe during an emergency.

Intercoms were among the first electronic devices to play a role in a security plan. School administrators continue to make widespread use of audio intercoms to order lockdowns or evacuations simultaneously. Teachers may use the same systems to contact the office for help with a disruptive student or a medical emergency.

Installed at office buildings and multi-tenant facilities, intercoms enable visitors to request access through locked entries. The stations allow operators to unlock associated doors and gates. People require intercoms to contact operators of parking lots and garages as the facilities are increasingly becoming unattended. Pair an intercom with external weatherproof paging speaker horns to extend a system’s range to include entries, courtyards, playgrounds, and other nearby outdoor areas.

Audio intercoms are incredibly reliable and easy to install with two-wire connections. And existing cable can frequently be re-used as end-users look to upgrade systems to take advantage of new features or a more modern appearance.

Emergency Stations

Emergency stations are ideal for security purposes in many outdoor locations. Intercoms mounted in compact wall boxes or modular emergency towers provide people a direct link to a two-way conversation with a security officer or local first responder. The audio input enables security staff to better respond to an emergency. Security personnel immediately know the exact location of incoming calls.

Emergency stations are commonly installed along pedestrian trails, in remote parking lots, athletic fields, and more. They are also valuable indoors in unattended lobbies, elevator banks, and stairwells. Unlike telephone-based systems, intercom stations require no POTS lines, eliminating monthly phone bills. Dispatch and phone lines remain open as intercoms provide a second communications path. The stations’ speakers can share both live and pre-recorded messages to warn people of a potentially dangerous situation.

The addition of video intercoms creates emergency stations that blend both sight and sound in a single station.

Emergency Notification Systems

Another way security professionals use audio is though recorded alerts delivered via emergency notification systems. These systems simultaneously warn hundreds—to thousands of people through a multi-faceted, network-centric approach. Alerts can be in the form of text messaging, social media posts, and email, along with audio warnings from speakers throughout a campus facility or an entire neighborhood. Audio has an advantage as it doesn’t require anyone to look at a smartphone to receive a notification.

High-power speaker arrays mounted on tall poles can transmit live and recorded messages at distances up to a quarter of a mile or more, depending on an area’s topography. Speakers may be mounted for omnidirectional and directional coverage. A few properly placed speakers are often enough to cover a large area.

Fire Alarm Systems

A fire alarm system, serving an entire building or multiple linked facilities, is often used to alert people of emergencies. A modern system can use text and email messages, sirens, strobe lights, or speakers to share alerts. The non-profit National Fire Protection Association, which creates standards and codes for fire systems, prefers voice or text messages as compared to sirens. The NFPA has found most people’s first reaction upon hearing a siren is to flee. And that might not always be the best choice.

A 2018 shooting at a Florida high school that left17 dead is an example. The shooter lured students and staff out of classrooms by pulling a fire alarm. Seconds later, a campus administrator issued a lockdown order. Mass confusion resulted from the seemingly conflicting alerts. One result of this shooting was NFPA Standard 72, which now calls on emergency notifications to take priority over other alarms.

Drones and Other Devices

Speaker-equipped unmanned aerial systems, or drones, provide yet another way to share audio messages. Although the small speakers can’t be heard over broad areas, they can hover over remote areas to reach people. Many agencies have passed laws regulating where drones may operate, make sure they are appropriate for your area.

Gunshot detectors also use audio for security and law enforcement purposes. These systems employ multiple sensors spaced throughout a coverage area to detect and record loud sharp noises and report it to law enforcement officers. The time it takes to reach multiple sensors helps pinpoint the location of the noise. Trained acoustic experts listen to the sound to determine if it was caused by a gunshot, a car backfire or another event. Many major cities employ gunshot detectors, yet there is debate about the technology’s accuracy. Also, the systems may record snippets of nearby conversations – a point challenged by civilians.

The use of these audio devices won’t necessarily eliminate risk, but it does provide security professionals with valuable information to help determine the best response. Not every picture tells the entire story.

This article originally appeared in the September October 2020 issue of Campus Security Today.


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