Voice evacuation and announcement system: why is an ordinary audio system not sufficient?
An emergency voice alarm system (voice evacuation) is a system that tells the people in a building, in spoken words, what to do in a fire or a similar emergency. A siren only says "something has happened"; a voice announcement says "people on the 3rd floor, please evacuate using the west staircase". In crowded and complex buildings, this is the difference that lets people know what to do. The same system is also used day to day for background music and general announcements — but emergency priority always overrides everything else.
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Selection guide and FAQ
The difference between ordinary audio system and voice evacuation system
| Topic | Ordinary audio system | Voice evacuation (EN 54) |
|---|---|---|
| Certificate | None | Control equipment EN 54-16, loudspeakers EN 54-24 certified |
| Fault monitoring | None — if loudspeaker cable breaks, no one would know | Line, amplifier and microphone are continuously monitored; fault is displayed on panel |
| Backup amplifier | None | An optional function under EN 54-16; if the design calls for it, a standby amplifier takes over from a failed amplifier |
| Backup power | None or limited | Battery provides standby time and alarm duration |
| Priority | None | Fire announcement automatically cuts off music and other announcements |
| Wiring | Standard cable | Fire-resistant cable; if the line breaks, the other zone continues to operate |
| Connection to the fire control panel | None | Triggered from the detection panel, makes zone-based announcements |
Speaker types
| Type | Where |
|---|---|
| Ceiling (recessed ceiling) | Office, corridor, store, hotel room — homogeneous sound distribution |
| Wall-mounted type (cabin) | Spaces without suspended ceiling, stairwell, technical area |
| Horn (ducted) | Parking lot, factory, open area — intelligibility in noisy and reverberant environment |
| Sound column (speaker column) | High-ceiling and reverberant spaces: mosque, sports hall, terminal |
| Outdoor area (IP class) | Facade, garden, field; water and dust-resistant enclosure |
Determining points in the design
- The system is built on the 100-volt line principle: loudspeakers are connected in parallel on one line and the power each one draws is set via its transformer. The high line voltage reduces losses on long cable runs but does not eliminate them; the cable cross-section is chosen from a voltage drop calculation. Adding loudspeakers also becomes easy — this is the most fundamental difference from 4–8 ohm home audio systems.
- Sound level alone is not enough; the message has to be intelligible. In a reverberant space, turning the volume up often does not improve intelligibility; the solution is more loudspeakers, at lower power and closer to the listener.
- Zoning is the evacuation scenario itself. In buildings that cannot be evacuated all at once, BYKHY Article 81/4-a requires the alarm to start in the zones affected and about to be affected by the fire, and to be brought into operation in the other zones in stages; which zone gets an evacuate message and which gets an alert message comes from the building’s emergency plan.
- BYKHY Article 81/7 lists the two forms of announcement together: automatically broadcast voice messages and live messages given by microphone from the fire control point. The recorded message is written short and clear; the live announcement microphone is for the fire brigade and staff.
- Loudspeaker lines are separated so that the other zones do not go silent even if one cable is damaged; cables to the amplifiers and loudspeakers must be able to withstand fire for at least 60 minutes (BYKHY Article 83/1-a).
- The system must be designed in coordination with the fire detection control panel. When a public address system is added later without proper integration with detection, the evacuation scenario cannot be executed.
- BYKHY Article 81/7 makes a voice alarm system mandatory in three cases: hotels, motels and dormitories with more than 200 beds; buildings open to the public, shopping centres, supermarkets, industrial facilities and similar buildings with a construction area over 5,000 m² or more than 1,000 total users; and all buildings with a structure height over 51.50 m.
A common assumption is this: a shop or workplace has an amplifier and loudspeaker system installed for music, and it is assumed that announcements will be made over it in a fire. But in such a system nobody notices when a loudspeaker line breaks, an amplifier failure gives no warning, the system goes silent when the power is cut, and it has no connection to the fire alarm panel. In a building where a voice alarm is mandatory, BYKHY Article 81/7 requires automatic voice messages and live microphone messages from the fire control point together; a music system without these functions does not meet that description. The existing sound system can often be kept and continue to serve everyday use; the emergency function is installed separately with a certified system.
Frequently asked questions
Is a voice evacuation system mandatory in my building?
For new buildings, BYKHY Article 81/7 applies: hotels, motels and dormitories with more than 200 beds; buildings open to the public, shopping centres, supermarkets, industrial facilities and similar buildings with a construction area over 5,000 m² or more than 1,000 total users; and all buildings with a structure height over 51.50 m. There is no separate voice alarm article for hospitals; a hospital taller than 51.50 m falls under point (c), while assessing it against the area and occupancy thresholds is an interpretation based on the definition of buildings open to the public. For existing buildings, the situation depends on any change of use and on the authority’s opinion.
Can I use my existing music system for evacuation?
No, if it is not certified or not connected to the fire alarm panel. But the existing system is not wasted: it can continue to be used for everyday music and announcements, while the emergency side is installed with certified equipment and takes priority. In some projects the existing loudspeaker cabling can also be reassessed.
How many speakers are required?
The number of loudspeakers is calculated from the size of the area together with the ceiling height, the loudspeaker’s dispersion angle, the ambient noise and the reverberation. In a noisy space the target sound level rises; in a reverberant space, rather than raising the volume, the loudspeaker needs to be brought closer to the listener. We explain the calculation method with examples in our guide to loudspeaker quantity and amplifier power.
Can announcements be made if the power is cut?
Yes. The system is designed with battery backup; after power loss it remains in standby mode for a certain period and carries sufficient energy to make announcements in an alarm situation. Battery capacity is calculated within the project scope and measured during periodic maintenance.
Can we determine the announcement text ourselves?
Yes, the pre-recorded messages are written for your building (floor, exit direction, a repeat in a second language if needed). A short, clear and slowly read text matters for intelligibility; what has happened and what people should do are stated plainly. We have collected sample texts in our guide to emergency announcement messages.