association info

BELLSONIC is an association, which began its activity in April 2000, embracing the Polish territory.

The associations goal is to spread the knowledge on modern audio techniques:
  • protecting peoples lives - sound evacuation techniques called Voice Alarm®,

  • &
  • protecting hearing from noise - reinforcing public areas using intelligent sound techniques, which fight reverberation noise
BELLSONIC achieves its goals by:
  1. pointing out the threats of civilians lives in public buildings, resulting from ineffective methods of informing about danger,
  2. opinioning the compatibility of sound reinforcement systems with the Voice Alarm® standard BS5839-8,
  3. propagating the use of modern sound techniques,
  4. offering advice and organisational help to those interested in the activity of the association, organising seminars, presentations etc. elaborating and distributing training materials in innovative sound techniques,
  5. collaborating with persons and institutions in collecting information and exchanging experiences about:
    • intelligent sound techniques
    • safety of civilians in public buildings
    • hearing hygiene and fighting interior noise
  6. pointing out public buildings, in which level of noise exceeds hearing safety standards,
  7. measuring and preparing expert reports on the above subject,
  8. representing members' opinions and attitudes to government authorities and administrative board,
  9. collaborating with government and non government institutions in complying the Polish regulations with European Union standards,
  10. collaborating with government and non government institutions in defining the directives for Voice Alarm®.
BELLSONIC Association joins specialists from different fields: architects, lawyers, doctors, scientists, acoustic-physicians, sound designers, interior architects, audio engineers, fire protection and safety specialists.

Voice Alarm®
Innovative sound techniques, which help evacuate people from public buildings.

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.

The transmission of intelligible message through the speakers includes the necessity of fulfilling strict technical conditions, which are:
  • high reliability of audio / sound equipment - even in critical situations
  • adequate quality of the spoken message emitter, that assures high index of speech intelligibility, min. 0,5 RASTI
Reverberant Noise
It is a physical phenomenon, which occurs in large areas with high ceilings. The surfaces (walls, ceiling and floor) reflect sound, causing long reverberation time.

The "reverberation noise" phenomenon takes place when sound energy, reflecting from the walls and ceiling, superimposes. It does not only lose its power but is reinforced 3dB higher.

The superimposing of sound waves results in the loss of clarity and intelligibility of the message (auditions and spoken messages) transmitted by the speakers, which makes them uncomfortable to listen to.

The characteristic point is, that the louder is the source (speaker - emits a larger energy), the bigger is the "reverberation noise" effect !

Stowarzyszenie BELLSONIC
tel./fax (0 58) 763 12 87, e-mail: