What is an Emergency Announcement System? How Does It Work and Where Is It Mandatory?

An emergency announcement system is an electronic security system that provides audible warnings and directional instructions to building occupants during fires, earthquakes, and similar emergencies. These systems aim to inform people of danger, direct them to appropriate exits, and, if necessary, facilitate the controlled evacuation of specific sections of a building.

Shopping malls, hospitals, hotels, airports, factories, high-rise buildings, and commercial buildings with high human traffic are among the significant application areas for emergency announcement systems.

Emergency announcement systems have different security requirements compared to public address systems that provide daily information and music broadcasts. The transmission of priority messages during a fire, monitoring system faults, the use of backup power, and speech intelligibility are paramount among these differences.

The primary purpose of an emergency announcement system is not merely to issue a loud warning; it is to reliably deliver the correct evacuation instruction, understandable to people, at the right time and to the correct zone.

What is an Emergency Announcement System?

An emergency announcement system is a professional voice alarm infrastructure that transmits automatically recorded messages or live announcements made by authorized personnel via microphone to designated building zones.

In international technical literature, these solutions are referred to as Voice Alarm System (VAS) or, when combined with public address functions, Public Address and Voice Alarm (PAVA).

The system can operate integrated with a fire alarm control panel or be manually activated by an authorized user in supported scenarios.

The main functions of emergency announcement systems include:

• Generating audible warnings during fire and other emergencies.

• Automatically broadcasting pre-recorded evacuation messages.

• Enabling authorized personnel to make live announcements.

• Transmitting different messages to different areas.

• Supporting phased or zoned evacuation scenarios.

• Monitoring faults in loudspeakers, amplifiers, power, and communication lines.

• Giving higher priority to emergency messages over other audio broadcasts.

An emergency announcement system is not a fire detector. It works in conjunction with a fire detection system to ensure that detected dangers are clearly communicated to building occupants.

How Does an Emergency Announcement System Work?

The operation of an emergency announcement system is based on the principle of receiving danger information, selecting the appropriate message, and transmitting it to the relevant areas.

For example, let's consider a fire detection system generating an alarm in a specific zone of a shopping mall.

The system can operate in the following stages:

1. The fire alarm control panel evaluates the event received from a detector or manual call point.

2. A command is sent to the emergency announcement system according to the defined cause-and-effect scenario.

3. The emergency announcement control unit determines which messages will be transmitted to which zones.

4. Normal music and general announcements in the affected zones are stopped or suppressed.

5. The pre-recorded evacuation message is broadcast via loudspeakers.

6. If necessary, authorized personnel provide live guidance using the emergency microphone.

7. The system continues to monitor for potential faults in the relevant hardware and communication lines.

This process is configured according to the approved fire and evacuation scenario.

Difference Between Automatic and Manual Announcements

Automatic announcement is the broadcasting of pre-prepared messages by the system based on defined events.

Manual announcement is when authorized personnel provide live guidance to building occupants via a microphone.

For example, while an automatic message might request the evacuation of a specific zone, authorized personnel can provide different guidance based on changing conditions.

However, manual intervention authorities, message priorities, and emergency procedures must be predefined.

What Devices Make Up an Emergency Announcement System?

Professional emergency announcement systems consist of more than just microphones and loudspeakers.

In a system used for life safety, various hardware components must work together reliably.

Emergency Announcement Control Unit

The control unit is the central management component of the system.

It manages automatic messages, live announcements, zone selections, and the system's operating conditions during an alarm.

In suitable systems, device statuses, error logs, and connection issues can be monitored via the control unit.

Emergency Announcement Microphone

The emergency announcement microphone allows authorized personnel to provide live voice guidance.

Some systems include selection buttons for making announcements to specific zones, emergency control switches, and status indicators.

These microphones may have different priority and supervision features compared to ordinary desktop announcement microphones.

Power Amplifiers

Amplifiers boost the audio signal from the control unit to a power level suitable for loudspeakers.

Professional systems use amplifiers with varying power and channel capacities.

When selecting amplifiers for emergency announcement applications, the total loudspeaker load, announcement zones, and redundancy requirements must be evaluated.

Emergency Announcement Loudspeakers

Loudspeakers are devices that deliver audible messages to building occupants.

For emergency evacuation systems, loudspeakers compliant with EN 54-24 are used.

When selecting loudspeakers, factors such as sound level, frequency characteristics, directivity, mounting location, and the acoustic properties of the environment must be considered.

Line Monitoring and Fault Supervision

In emergency announcement systems, the status of loudspeaker and communication lines must be monitored.

Suitable systems provide detection of open circuits, short circuits, and specific hardware faults.

This feature helps identify the risk that the system might appear to be operating normally but fail to provide audible warnings in certain areas.

Backup Power Unit

An appropriate backup power infrastructure is required for essential emergency announcement functions to continue during a power outage.

Battery capacity must be calculated based on standby consumption, expected load during an alarm, and the operating times required by relevant project standards.

What is the Difference Between an Emergency Announcement System and a Public Address System?

Public address systems are used for daily announcements and music broadcasts.

In emergency announcement systems, the primary priority is the transmission of life safety messages.

This comparison does not imply that a general-purpose audio system can be automatically converted into a certified fire voice evacuation system through software.

The presence of a public address system in a building does not indicate that the building's mandatory emergency announcement requirements are met.

However, with appropriate certification and system design, general announcements, background music, and emergency announcement functions can be combined within the same infrastructure.

How Are Emergency Announcement Systems Categorized?

Emergency announcement systems can be examined based on their architectures as centralized, distributed, and IP-based solutions.

Centralized Emergency Announcement Systems

In a centralized architecture, control and amplification equipment are typically located in a specific technical room or cabinet.

Loudspeaker lines are distributed from this central point to the relevant building zones.

This structure can be considered particularly in applications where a limited number of buildings or zones are managed from a single center.

Distributed Emergency Announcement Systems

In a distributed architecture, different components of the system can be located at multiple technical points.

For example, in large campuses or facilities consisting of different buildings, amplifiers can be positioned closer to the relevant areas.

The suitability of this approach depends on the system's network topology, redundancy capacity, and the manufacturer's approved architecture.

IP-Based Emergency Announcement Systems

In IP-based systems, audio and control information can be transmitted over an appropriate network infrastructure.

This method can provide flexibility in terms of system expansion and centralized management in comprehensive projects.

However, IP-based emergency announcement systems should not be evaluated under the same reliability conditions as ordinary office networks.

Network redundancy, cybersecurity, communication latency, power continuity, and fault monitoring are fundamental elements of the design.

What is Zoned Evacuation in an Emergency Announcement System?

Zoned evacuation is the transmission of different audible instructions to different sections of a building.

For example, in a multi-story building, while evacuation of the floor where a fire occurred is initiated, a different directive might be applied to other floors.

This approach is referred to as zoning or segmentation.

However, zoned evacuation is not merely about creating different loudspeaker groups within the system.

When determining the evacuation strategy, the building's fire compartments, intended use, stairwell capacity, exit routes, and relevant safety plan must be evaluated together.

Which zone is to be evacuated first should be determined not by the preference of the person installing the emergency announcement software, but according to the approved fire safety scenario.

Why is Speech Intelligibility Important in Emergency Announcement Systems?

The effectiveness of emergency announcement systems depends more on the intelligibility of the message than on the loudness of the sound from the loudspeakers.

For example, in a large factory, the sound from loudspeakers might be audible, but the evacuation instruction might not be understood due to machine noise.

Similarly, in shopping malls or large atriums with extensive marble, glass, and concrete surfaces, reverberation can make speech difficult to understand.

Key factors affecting speech intelligibility include:

• Ambient noise.

• Room reverberation time.

• Loudspeaker directivity.

• Loudspeaker placement and mounting height.

• Sound pressure level.

• Frequency characteristics.

• Timing differences between loudspeakers.

What are STI and STIPA?

STI (Speech Transmission Index) is a metric used to assess how intelligibly speech is transmitted through an audio system and acoustic environment.

STIPA, on the other hand, is a method used to evaluate speech intelligibility with appropriate measurement devices.

The IEC 60268-16:2020 standard describes STI calculation and measurement methods. The standard also has a correction dated July 2025.

This standard alone does not define a universal acceptance threshold for all emergency announcement systems.

Acceptance criteria must be defined according to the applicable design standard and project requirements.

How to Select Emergency Announcement System Loudspeakers?

Loudspeaker selection should be made according to the architectural and acoustic characteristics of the building.

The EN 54-24 standard defines the requirements and test methods for loudspeakers used in fire voice alarm applications.

Type A loudspeakers within the scope of the standard are generally for indoor applications, while Type B loudspeakers are generally for outdoor applications.

However, EN 54-24 compliance alone does not guarantee that a loudspeaker will provide sufficient speech intelligibility in a specific building.

What is a 100 V Line System in Emergency Announcement Systems?

100 V line technology is widely used in professional public address and emergency announcement projects.

In these systems, loudspeakers with appropriate transformers can be connected to a loudspeaker line at specified power taps.

This ensures that loudspeakers at different points are powered via common amplifier outputs.

However, the use of a 100 V line does not mean that cable losses or system capacity calculations are eliminated.

How is Amplifier Power Calculated?

When determining the required amplifier power, the selected power taps of the loudspeakers connected to the relevant line are summed.

However, in actual amplifier selection, in addition to the total loudspeaker load, cable losses, manufacturer limits, power reserve, simultaneous broadcast scenarios, and redundancy requirements must be evaluated.

Therefore, the exact amplifier power cannot be determined solely based on the number of loudspeakers in the building.

Line Monitoring and Redundancy in Emergency Announcement Systems

Some faults occurring in emergency announcement systems can prevent audible evacuation messages from reaching certain areas.

Therefore, monitoring essential system components is crucial.

Loudspeaker Line Monitoring

In suitable systems, fault conditions such as open circuits and short circuits in loudspeaker circuits can be monitored.

In some projects, A/B line configurations or different redundant loudspeaker connection architectures approved by the manufacturer may be used.

The purpose of these structures is to reduce the risk of specific single faults preventing the entire area from being warned.

However, it should not be assumed that there is a single mandatory loudspeaker cabling scheme for every building.

Backup Amplifier

In supported systems, if an amplifier fails, an appropriate backup amplifier can be planned to take over.

The reliability of this function depends on the design of the relevant system and approved product specifications.

Power Continuity

A backup power system must be used to ensure essential announcement functions continue during a mains power outage.

Power calculations must consider standby time, alarm operation time, amplifier loads, and relevant standard requirements.

Where is an Emergency Announcement System Mandatory?

In Turkey, the primary regulation concerning emergency announcement systems is the provisions of the Regulation on Fire Protection of Buildings.

According to the seventh paragraph of Article 81 of the Regulation, systems that provide evacuation or relocation guidance within a building via automatic voice messages and live announcements from the fire control center are mandatory in the following structures:

1. Hotels, motels, and dormitories with more than 200 beds.

2. Public buildings, shopping malls, supermarkets, industrial facilities, and similar structures with a building construction area larger than 5,000 m² or a total user capacity exceeding 1,000 people.

3. All buildings exceeding a structural height of 51.50 meters.

These criteria are the thresholds defined by the relevant article. Other provisions applicable to existing or special-purpose structures and project approval conditions must be evaluated separately.

The same article of the Regulation also stipulates that emergency announcements must have priority over general announcements and background music.

The fifth paragraph of Article 81 contains conditions related to the sound level of audible warning devices. It defines a minimum difference of 15 dBA relative to the ambient sound level and specific sound level requirements for certain areas.

All these values should not be applied as a single loudspeaker setting independently of acoustic project and speech intelligibility requirements.

Is a Siren Required Where an Emergency Announcement Loudspeaker is Present?

The fifth paragraph of Article 81 of the Regulation contains a provision stating that a separate siren system is not required in spaces where an emergency announcement system loudspeaker is present.

However, its implementation must be evaluated in conjunction with ensuring compliant audible warning in the relevant space and meeting all project requirements.

Therefore, the removal of sirens from a project should not be decided solely based on the presence of any loudspeaker in the building.

Should Emergency Announcement System Cables Be Fire Resistant?

Article 83 of the Regulation on Fire Protection of Buildings contains provisions regarding certain signal and power cables that must remain operational during a fire.

Within this scope, the relevant cables leading to the voice evacuation system amplifiers and loudspeakers must be capable of resisting fire for at least 60 minutes under the conditions specified in the regulation.

It is also stipulated that cables must be tested and certified according to relevant standards.

However, a halogen-free cable and a cable capable of maintaining circuit integrity during a fire do not denote the same technical characteristic.

Furthermore, cable routes, connections, and relevant support elements must also be evaluated to support the required operational continuity.

Which Standards Should Emergency Announcement Systems Comply With?

Important standards used in fire-purpose voice evacuation systems are as follows:

It should be noted that the EN 50849:2017 standard excludes sound systems used for fire evacuation purposes.

Therefore, EN 50849 should not be considered as the sole equivalent of EN 54 requirements in fire evacuation systems.

For projects to be implemented in Turkey, current TS equivalents, product certificates, and relevant regulatory provisions must be checked separately.

What to Consider When Choosing an Emergency Announcement System?

For correct system selection, the characteristics of the building to be protected and evacuation requirements must first be determined.

Building and Evacuation Zones

The building's number of floors, intended use, human density, evacuation zones, and emergency scenarios must be evaluated.

Acoustic Performance

Ambient noise, reverberation, loudspeaker placement, and speech intelligibility requirements must be considered.

System Architecture

The suitability of centralized, distributed, or IP-based infrastructure for the project must be determined.

Fire Alarm Integration

The compatibility of connection methods and alarm scenarios to be used with the fire panel must be verified.

Hardware and Capacity

Amplifier powers, loudspeaker lines, number of announcement zones, and backup capacity must be calculated.

Standard Compliance

Product certificates and conformity documents must be evaluated according to the entire system to be used.

Maintenance and Technical Service

Monitoring system faults, performing necessary functional tests, and ensuring ongoing technical support must be planned.

Technical Checklist for Emergency Announcement System Installation

The following checklist can be used as an initial assessment for system integrators and project engineers:

• Have the building's emergency announcement obligation and relevant regulatory conditions been checked?
• Have evacuation zones and the cause-and-effect matrix been determined?
• Has EN 54-16 compliance for control and announcement devices been verified?
• Has the relevant EN 54-24 compliance for loudspeakers been checked?
• Has loudspeaker placement and acoustic analysis been performed?
• Have speech intelligibility acceptance criteria been defined?
• Have amplifier power and loudspeaker line loads been calculated?
• Have the necessary loudspeaker line fault monitoring functions been checked?
• Have fire-resistant cabling requirements been evaluated?
• Have main and backup power sources been calculated?
• Has fire alarm panel integration been tested?
• Has the priority of emergency announcements over public address been verified?
• Have electrical, network, and hardware fault scenarios been tested?
• Have live microphone and automatic evacuation messages been checked?
• Has the commissioning report and maintenance program been prepared?

This checklist aids in project evaluation. Definitive system design must be carried out in accordance with competent engineering work and relevant standards.

Periodic Maintenance in Emergency Announcement Systems

Emergency announcement systems must be regularly inspected after installation is complete.

The system appearing to operate normally does not guarantee that correct and intelligible evacuation messages are broadcast from all loudspeakers.

During periodic maintenance, the following functions should be evaluated:

• Control unit and system status information.

• Operating status of amplifiers and loudspeaker lines.

• Emergency announcement microphone and zone selection.

• Transmission of automatic messages to correct zones.

• Priority of general announcements and emergency announcements.

• Backup power and fault notifications.

• Integration with the fire alarm control panel.

• Necessary acoustic and speech intelligibility checks.

The scope and frequency of maintenance must be determined according to manufacturer instructions, relevant standards, and the facility's risk conditions.

GüvenlikOnline's article titled How to Perform Periodic Maintenance in Fire Detection Systems? can also assist in evaluating maintenance processes for fire safety infrastructures.

In Which Buildings Are Emergency Announcement Systems Used?

Emergency announcement systems can be evaluated in various facilities based on regulatory requirements, as well as the building's intended use and risks.

It should not be assumed that the same product architecture will be suitable for every application area.

For example, while loudspeaker directivity and intelligibility might be prioritized in a high-noise factory, evacuation zones and system continuity could create more complex requirements in a high-rise building.

Frequently Asked Questions

Are an emergency announcement system and a fire alarm system the same?

No. A fire detection system detects fire indicators and generates an alarm. An emergency announcement system, with appropriate integration, converts this alarm into audible evacuation instructions.

What is the purpose of an emergency announcement system?

It supports safe evacuation and guidance processes by transmitting automatic or live voice messages to building occupants during emergencies.

Is an emergency announcement system mandatory in every building?

No. Mandatoriness depends on conditions specified in regulations, such as the building's intended use, number of beds, construction area, user capacity, and height.

Can an emergency announcement system broadcast music?

Yes. In suitable systems, general announcements and background music can be broadcast. However, emergency messages must have priority over other broadcasts.

Why is EN 54 certification important in emergency announcement systems?

The relevant parts of the EN 54 series define the performance and conformity requirements for control and loudspeaker equipment used in fire-purpose voice alarm systems. However, the entire system also needs to be correctly engineered.

Is it mandatory to use a 100 V line in an emergency announcement system?

100 V line technology is a common application. However, the audio distribution method and system architecture to be used must be determined according to the manufacturer's supported solution and project requirements.

Does an emergency announcement system work during a power outage?

With appropriate backup power infrastructure, essential emergency announcement functions can be sustained during a power outage. Operating time depends on system design and power capacity.

What is an STI test in an emergency announcement system?

An STI test helps evaluate speech intelligibility. Hearing the sound and understanding the evacuation instruction are different performance criteria.

Proper Project Planning is at the Core of a Reliable Emergency Announcement System

Emergency announcement systems are crucial life safety infrastructures that ensure people are correctly informed during fires and other emergencies.

The effectiveness of these systems does not solely depend on the number of loudspeakers or amplifier power.

Speech intelligibility, correct evacuation scenarios, integration with the fire alarm system, backup power, fault supervision, and regular maintenance must be evaluated collectively.

The success of a reliable emergency announcement system should be measured not only by the broadcasting of the message but by its timely, intelligible, and accurate delivery to the relevant individuals.

GüvenlikOnline's content titled What are Low Current Systems? Types and Technical Guide also discusses the relationship between emergency announcement and public address systems and other building technologies.

References

1. T.C. Ministry of Justice — Regulation on Fire Protection of Buildings — Provisions on emergency announcement obligation, audible warning, cabling, and maintenance.

2. EVS — EN 54-16:2008 — Voice alarm control and indicating equipment.

3. EVS — EN 54-24:2008 — Loudspeakers for voice fire alarm systems.

4. EVS — CEN/TS 54-32:2015 — Planning, design, commissioning, and maintenance of voice alarm systems.

5. IEC — IEC 60268-16:2020 — STI measurement method and speech intelligibility.

6. IEC — IEC 60268-16:2020/COR1:2025 — 2025 correction of the speech intelligibility standard.

7. EVS — EN 50849:2017 — Emergency sound systems other than for fire evacuation.