An Emergency Voice

Will your message be heard during an emergency?

• By Bruce Czerwinski
• Sep 19, 2022

In early July, residents living in a South London tower block “found out through WhatsApp” about a fire raging above them because they allegedly didn’t hear any alarms. A fire broke out at the building shortly after midday on a Sunday afternoon, and according to a news report, residents said alarms did not go off inside the building.

One resident said, “I can’t believe we had to message each other on WhatsApp groups and knock on each other’s doors just to tell each other that there was a huge fire in our own building.” Another resident who lives on the 20th floor of the 21-story building said, “I did not hear an alarm. I think there was a fire alarm on the ground floor, but I could not hear it clearly on the 20th.”

Luckily, no one was seriously injured. However, the incident has shed light on the building’s fire and emergency communications system.

Communicating in an Emergency
You easily could have a situation where a small- or large-group of people need to leave a building, facility or area, or need evacuation because of a security or safety threat. Regularly, situations such as fire, weather, a bomb threat, an active shooter or other situations may require security teams to execute their emergency plans and communicate instructions.

What needs to be “usual,” and what needs to happen during an emergency is clear communication.

Most security operations employ emergency communications that include alerts and warnings; directives about evacuation, curfews, and other self-protective actions; and information about response status, family members, available assistance and other matters that concern response and recovery. Those emergency communications can help ensure public safety, protect property, facilitate response, elicit cooperation, instill public confidence and help people to reunite.

The extent to which people respond to a warning message is influenced by many factors, including individual characteristics and perceptions, whether the message comes from a credible source, how the message is delivered, if the message contains specific and adequate information, if it is in sync with other information being disseminated, and if it is accessible to the whole community.

People will also respond to an emergency message that is clear and understood.

That is where audio solutions such as intercoms and IP speakers that communicate clearly can play a critical role in emergency communications. HD voice solutions can convey important messages that a video surveillance camera, or VMS or access control solution cannot.

High-quality audio, via operational public address solutions, can keep everyone informed during an emergency with live or pre-recorded messages. If the situation is fluid, as many security situations can be, security teams can quickly alter the message. They can even use individual zoning to customize messages to specific areas, as the situation unfolds. Once the building is evacuated, public address messages via IP speakers can keep everyone informed about how long they might need to stay out of the building, when they can go back inside, or whether they should go to another area.

Crystal-Clear Audio
What does clear, intelligible, high-quality audio in emergency communications mean? Do your current emergency communications messages provide clear, intelligible audio? We suggest that you measure it by using an Intelligibility Scorecard that we have found used by the most knowledgeable thought leaders in audio. Try using it to help you evaluate your critical communication solutions.

When looking at how your intercom or IP speaker solution performs (or does not), make sure that the solution employs:

• A 10W Class D Amplifier, powered over PoE, so that speaker is capable of delivering more than 116dB.
• Acoustic Echo Cancellation, which prevents feedback and enables clear and hands-free communication, even at high volumes (95dB).
• Automatic Gain Control: A voice that is too loud or too weak (too close or too far) will be leveled out to an undistorted and clear signal.
• Anechoic Speaker Design: Prevent distortion from "standing waves,” which is the combination of two waves that are moving in opposite directions. Standing waves form when a wave bounces back and forth in a situation that produces constructive interference.
• A Rigid Stable Frame with microphone damping to isolate microphones from vibrations at loud volumes.
• Acoustically Transparent Poke Screen: A feature that makes the speaker vandal resistant while maintaining the quality of the audio.
• Talkback and Ambient Listening functions, to enable your team to act in real time and with clear communication, in all types of environments and situations. 
• A Self-Checking function to detect whether there are any faults in the network or speaker electronics.

Those features that remove the noise surrounding the intercom or speaker means that inside the solution, the microphone signal is automatically being measured and is calculating the noise components in that signal. That process effectively removes noise components, leaving a clean speech signal even if the original speech level is below the level of the surrounding noise. The result is a clear Open Duplex conversation, even with a passing train in the background or talking from inside a car while stuck in front of a barrier, or the sounds and commotion that take place in an emergency.

Loud and Clear
Emergency communications cannot include bad audio. It should incorporate solutions that are intelligible in even the most challenging circumstances that enable security teams to deliver clear instructions with intelligible voice and audio whenever the need arises and to improve the quality of assistance provided by security guards and control rooms.

In today’s ever-changing and ever increasing and complicated risk environment, the importance of high-quality, clear audio cannot be understated. It is purchase a communications system and send emergency communications if the audible announcements and messages cannot be heard, or understood. It is time to stop accepting bad audio, and instead, embrace a solution that offers audio and voice technology that allows people to hear, be heard, and be understood in every situation.

This article originally appeared in the September / October 2022 issue of Security Today.