This informal CPD article, ‘Sound under control: How acoustic simulations are changing the approach to designing Voice Alarm Systems’ was provided by Katarzyna Lenczewska of Ambient System, a European producer and provider of modern PA/VA solutions for the dynamically developing security communication and audio industries.
Introduction: Designing Voice Alarm Systems in the digital age
Contemporary architecture presents designers with complex challenges. Voice Alarm Systems are among the crucial safety systems whose task is to convey information to building occupants in the form of voice messages. The effectiveness of a Voice Alarm System is closely linked to the intelligibility of the reproduced messages, which is influenced by many factors. Designing a Voice Alarm System requires a precise analysis of, among other things, the complexity of spaces, the variety of building materials and noise sources. Traditional design methods often fall short in intricate projects where designers encounter numerous such challenges simultaneously.
This is where acoustic simulations come onto the scene – a digital tool in Voice Alarm System design. Advanced software allows for the creation of a virtual model of the building and the precise analysis of sound propagation, optimizing loudspeaker placement, sound pressure level (SPL) and speech transmission index (STI).
Acoustic simulation under the microscope
Acoustic simulation is the process of modeling sound behavior in a given space using specialized software. The basis of the simulation is a three-dimensional model of the object, taking into account data on geometry, building materials and the type and placement of sound sources. The software simulates the propagation of the acoustic wave in this model, allowing for the visualization of key sound parameters.
The designer analyzes key parameters – from sound pressure level (SPL) and reverberation time (RT) to the speech transmission index (STI).
Thanks to simulations, designers gain the ability to precisely optimize the acoustics of a building at the design stage, which avoids costly corrections during implementation. Simulations minimize the risk of expensive design errors and become key to creating safe and acoustically comfortable spaces.
Oslo Atrium: Acoustic analysis in practice
The renovation project of the Oslo Atrium is an example of a real challenge for an acoustician developing an acoustic simulation.
The area under analysis is an open public space connecting 8 floors of the building. The volume is characterized by its enormous size, long reverberation time and limited possibilities for acoustic adaptation.
Methodology and criteria
The analysis, prepared using EASE software, focused on three parameters: sound pressure level (SPL), speech transmission index (STI) and reverberation time (RT).
Design assumptions:
- The system should ensure sound reproduction at a level of 86 dB SPL(A).
- The average STIPA value should be no less than 0.60.
- The reverberation time in the volume should not exceed 2s.
From model to implementation
Using the design data, a 3D model of the building was created, in which 219 sound sources, representing fire safety loudspeakers compliant with EN54 standards, were placed.
The simulations showed the necessity of using highly directional loudspeakers (linear array type ABT-LA60 was chosen for this role) and ceiling loudspeakers with an extended frequency response (ABT-S2010).
Through acoustic simulation, sound-absorbing materials in the form of acoustic panels, perforated boards and acoustic plaster were also selected.
Conclusions: The future of acoustic design
The Oslo Atrium project proves that acoustic simulations are not the future, but the present of Voice Alarm Systems design. The use of computer acoustic simulation tools in the design process allows for:
- Early detection and elimination of problems, saving time and money.
- Optimization of the project, guaranteeing intelligibility and safety.
For designers, this is a signal: acoustics is entering the digital age and simulations are becoming an indispensable tool.
We hope this article was helpful. For more information from Ambient System, please visit their CPD Member Directory page. Alternatively, you can go to the CPD Industry Hubs for more articles, courses and events relevant to your Continuing Professional Development requirements.
REFERENCES
- https://www.nielstorp.no/en/project/oslo-atrium-2/
