We Hear You
Intercoms necessary to order lockdowns, or evacuations
- By Brad Kamche
- October 01, 2020
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 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 & Life Safety.