Providing security and safety at multifaceted facilities such as airports can be a daunting and overwhelming task. State-of-the-art technology and security systems play a vital role in guaranteeing safety from dangers such as fire, terrorism and theft.

In recent years, public address and voice alarm systems (PAVA) have increasingly become part of the security mix at airports, a progression from their original role of transferring information to the public and between staff.

The case of the bombing at Domodedovo Airport in Moscow, Russia, on 24 January this year, once again highlighted their importance. After the detonation of the bomb, which left 36 people dead and 180 injured, eye witnesses and passengers who were stuck at the airport criticised the fact that no announcements were made, leaving them confused and unaware of the risks.

According to the UK-based provider of voice alarm systems, Baldwin Boxall, research has shown that in an emergency people will react without confusion or panic if they receive a clear and intelligible message. PAVA systems for airports, installed alongside fire detection and video surveillance solutions, are based on this idea.

"A voice alarm system provides controlled and phased evacuation."

Voice evacuation

Public address systems (PA) are commonly used to page and relay messages to people in an airport. Voice alarm systems (VA) have the same benefits and in the event of an emergency the system will instigate the automatic evacuation of the airport.

Under normal circumstances, VA systems serve as a public address system, playing advertisements, background music and timed message announcements. In emergency situations, however, whether in airports, train stations or other buildings, voice alarm systems are an essential tool to conduct fast and controlled evacuations, giving instructions and reducing panic.

"Current systems are now much more than just a basic PA system as they are used to both control the evacuation of the airport during an emergency or terrorist threat and also broadcast passenger and flight announcements to assist with simultaneous passenger movement," says Baldwin Boxall marketing manager, Alison Cousins. "Systems have the capability to be linked into building management systems and flight information display (FID)."

Bells and sounders only give a warning but do not indicate the nature of an emergency. "A voice alarm system provides controlled and phased evacuation," explains Cousins. "Pre-recorded messages in different languages can be automatically broadcast to ensure a safe evacuation. It is also a great asset in case of terrorism or bomb threats as it is not always safe simply to evacuate the building but move people to safer locations within a building."

People are informed about what is happening and what their next steps have to be. Fire officers, building managers and any other emergency commissioner can broadcast at any time during the situation.

"Two completely different situations can result from an emergency situation with or without a controlled voice evacuation."

According to Baldwin Boxall, two completely different situations can result from an emergency situation with or without a controlled voice evacuation. If no system is in use, vital time could be lost as people do not know on how to react to an alarm sound. When they eventually start to move they are likely to exit via the same route they entered, which may be the longest or most dangerous route.

Airports are usually divided into separate areas or zones. With a VA system in use, messages can be broadcast to areas at risk, help evacuate areas of high risk, alert areas of low risk and prevent people from moving into danger areas with real-time information. The best outcome is a calm, controlled and safe evacuation.

PAVA equipment

PAVA systems at airports must provide exceptionally high-quality speech reproduction, multilingual information and evacuation messages as well as a connection to automatic passenger information systems, real-time announcements and automatic routing of messages and background music.

Especially in emergency situations, the perfect combination of high-standard technologies and tools is essential. The microphone controller is the centrepiece of the system. A designated person to control the evacuation can send pre-recorded and live messages to loudspeakers all over the airport. According to Alison Cousins, quality is essential: "Audio quality is a serious factor in such large open spaces and it is vital that a full acoustic design is undertaken to ensure audibility at all times."

Special fire microphones can be located in different parts of the airport. In the case of an emergency these have top priority and override all other microphones and inputs to the voice evacuation system.

Another vital element is the voice alarm router, which is connected to the fire detection system of the airport. If the fire alarm goes off the VA system is triggered to evacuate and alert people automatically. Amplifiers receive input from the microphone and broadcast it to the relevant zones of an airport. A voice evacuation system must work even if the main power supply has failed. High-power batteries keep the system running in this case.

Dubai International Airport, situated in the largest city of the United Arab Emirates (UAE), is a major aviation hub in the Middle East. Despite an elaborated security and fire alarm system, the airport houses a well-thought-out PAVA system, supplied by Bosch Security Systems. More than 120 active line arrays, 3,500 ceiling speakers, which are driven by more than 300 amplifiers, 250 sound projectors and have been installed on Terminal 3 and Concourse 2 of the airport.

According to Bosch Security Systems, the heart of the PAVA equipment at the terminal is the central control system, which takes care of central logging, redundancy handling, PC call-station functionality and the interfacing to the automatic announcement system, flight information and building management system. The control system is also the main point of connection with the fire alarm system – of vital importance at an airport of the size of Dubai International.

New European standard in April 2011

To guarantee a smooth and controlled evacuation, the EU has implemented a new European standard, which comes into force in April 2011. The EN 54, which is a standard for fire detection and fire alarm systems, also includes regulations for voice alarm control and indicating equipment (VACIE) and loudspeakers.

Installers and consultants have to follow these new regulations in order to maintain the continuity of quality and safety when designing and installing voice alarm systems. "To comply with the standard, voice evacuation systems must be tested by an approved third party testing house," says Alison Cousins. The standard will enable better integration of VA and PA and plays an important role for voice evacuation at airports throughout Europe as member states of the EU will be obliged to replace their local standards with the EN 54 standard.

Product engineering manager at the UK-based provider of voice alarm systems and microphones, ASL Safety and Security, Steve Harrison, said in a statement published in summer 2010 that the new standard "will apply directly to anything that a manufacturer refers to as VA equipment or, more specifically, control and indicating equipment."

"To comply with the standard, voice evacuation systems must be tested by an approved third party testing house."

According to Harrison, a notable characteristic of the new standard is that voice alarm systems are required to operate in at least three distinct functional conditions: the quiescent condition where it is inactive or simply playing music, an active alarm condition where it is evacuating people, and a fault warning condition.

"In the same way that all fire alarm systems have to be accredited by an approved testing house before they can be sold, VA systems are now going to be subjected to similar scrutiny," he continued. "This is a sea change in the voice alarm sector and will have the welcome effect of levelling the playing field. But there are enough nursery and fairy tales cautioning us to be careful what we wish for to sound a note of warning."

Public address and voice alarm systems have moved on from their basic role as information conveyor tools to a critical element of the safety and security-mix of an airport. During an emergency or a terrorist threat voice alarm systems are a valuable factor for a calm and controlled evacuation and investing in a high-quality PAVA system equals investing in the safety of passengers and airport staff alike.