A Voice Alarm system (sometimes called a voice evacuation system or VACIE (Voice Alarm Control and Indicating Equipment)) has been proven to be much more effective than basic alarm bells and sounders in facilitating an emergency evacuation of a building.

Research has shown that people experience much less panic and confusion in an emergency situation when given instructions by a clear and intelligible message.

Voice Alarm systems exploit phased zonal announcements to strategically clear areas in a carefully coordinated pattern, with the areas closest to danger emptied first and surrounding areas put on ‘alert’. This reduces delays caused by bottlenecks on stairwells, for example.

A Public Address (PA) system typically broadcasts audio, either background music or announcements from a member of staff, throughout a facility. When a PA system will also be used for Voice Alarm (VA) important legislature (British Standards and European Law) governs design, functionality, installation and maintenance to ensure critical emergency messages are clearly delivered by a system that is appropriately robust for life safety.

Such legislature will be observed by the Local Authority when signing off safety certificates and licenses.

BSEN60849: 1998. Sound systems for emergency purposes

  • The Voice Alarm System needs to achieve a minimum of 0.5 on the Speech Transmission Index (STI) in all locations at all times
  • The system shall have automatic fault monitoring and reporting of all equipment and software
  • A secondary power supply is required (such as batteries, in addition to mains power), able to provide power for 24 hours in quiescent mode followed by 30 minutes of full-level emergency speech broadcast
  • System robustness: Failure of a single amplifier or loudspeaker must not result in the loss of coverage in the zone

BS5839-8: 2013. Fire detection and fire alarm systems for buildings

As buildings vary in size and complexity the VA system required on the site will vary, but for a large complex this code of practice for the design, installation, commissioning and maintenance of voice alarm systems typically requires that a system must exceed a standard PA system in the following ways::

  • Fault monitoring for all components in the system
  • For venues with over 500 capacity the system should utilise interleaved loudspeaker circuits (so that adjacent loudspeakers feed from different cables and amplifier channels), thus providing a working backup if one circuit / amplifier channel fails
  • Public testing should be carried out no less than quarterly, but ideally monthly
  • Only independently certified components (bearing CE mark) should be used - as per European Standard BS EN54
  • Cabling must be fire protected (Crossover typically use Low Smoke Zero Halogen (LSZH) cables in many ‘standard’ installs for additional safety too)

For VA/PA systems in shopping centres, warehouses and stadiums, Crossover will ensure legal compliance for your peace of mind and offer further helpful functionality. We often design the voice alarm system so that in an emergency situation the recorded voice messages can be supplemented by spoken messages from the management personnel, avoiding the "false alarm" mentality. The system will also intelligently work in conjunction with your fire alarm, and also to automatically cut any ambient music to allow the alarm to be heard clearly.

Whether your requirement is for a simple recorded voice alarm system, or a fully automated and zoned audio system that performs multiple functions, we’ll design the solution from scratch to ensure that our proposals match your site perfectly. We will advise you whether an analog, digital, wireless, or IP-based system will be most appropriate, taking into account possible future needs of your business. We will design and install a cost effective solution that is easy to use, rock solid, and delivers your message with clarity.