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ATTENTION - since Yanuary 2004 there is an obligation to equip every public building with Voice Alarm system - the regulation of Ministry of Internal Affairs and Administration in Poland.

The first Voice Alarm was applied during World War II in England, where they used speakers to transmit warnings about attacks on airports, seaports and streets.

The boom of the Voice Alarm technology appeared after the tragedy that took place in London's subway at Kings Cross

Independent research showed, that alarming of danger by using traditional methods like sirens and alarm bells, was not only delayed in transmission but also people didn't react to it by evacuating themselves. They usually waited for more evidence of the danger. As a result, people kept ignoring the alarm signals and headed in the wrong direction, causing bigger danger by blocking the exit and trampling over each other.

The same research proved that transmitting spoken messages through the Voice Alarm would have helped evacuate people not only through the right exit but also in the right time.

The sound amplification system technique used in public buildings was described as a specification "Sound Systems Specification used for Safety" in the international norm IEC 849 from the year 1989.

More detailed criteria are defined by the British building standard BS5839-8, called the Voice Alarm standard, which eliminates the inaccuracies occurring in IEC 849 in requirements concerning high speech intelligibility degree and selection of the right audio equipment

The use of Voice Alarm in a public building means replacing typical fire signals - bells and sirens, with adequate speakers, capable of transmitting clear and intelligible spoken messages.

Replacing those sirens and bells with speakers transmitting messages, includes the necessity of fulfilling strict technical conditions, which are:
  • high reliability of audio equipment - even in critical situations
  • adequate quality of the spoken message emitter, that assures high index of speech intelligibility, min. 0,5 RASTI
  • BS5839-8 - was the basic standard, which many organisations and audio engineer environments wanted to introduce as a regulation in other countries of European Union.
In the year 2000 in Europe a new norm EN60849 came to life, which partially concerns the Voice Alarm basing on the British Standard. It's Polish equivalent PN-EN60849 "Voice Alarm Systems" is functioning from March 2001.

In Technology section we present the innovative sound techniques and industrial technologies of the Voice Alarm.

If you have any information, ideas or problems concerning the above, send them by e-mail


BELLSONIC Association
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