Sound Reinforcement Solutions for Emergency Communication Systems
Why AV Integrators Should Be Involved in MNEC Solutions
The topics of Mass Notification and Emergency Communications (MNEC) initially conjures us mental images of a smoky room illuminated by flashing strobes. A barely intelligible message from a 4-inch loudspeaker attempts to cut through the din and deliver life-or-death instructions to the building’s occupants. Fortunately, this often works, and lives are saved.
A major problem is that this mode of message broadcasting does not scale with room size. This results in large, noisy, reverberant spaces being served by the same limited-fidelity strobe loudspeakers as the small, dead office environment. The intuitive “fix” is to do what a lighting designer would do to achieve more illumination for a dark room – just add more fixtures. Unfortunately, sound isn’t light, and adding more loudspeakers can actually reduce the intelligibility of the emergency messages. The MNEC community has learned the hard way that a broader pallet of tools and different type of expertise are required to deliver MNEC messages in large spaces.
The good news is that both the tools and the expertise already exist. Nothing new needs to be invented. The reproduction of intelligible speech in large, noisy, reverberant spaces is right up the alley of the sound reinforcement industry. In fact, there is a good chance that the difficult acoustic space that can’t be reached by fire strobe messages already has a sound reinforcement system that is used daily to communicate to the occupants of the space. It makes perfect sense to route the emergency announcements to the house sound system, and that is exactly what NFPA72 has been expanded to allow.
There two paths for bridging the divide between the fire alarm and sound reinforcement industries in order to increase the effectiveness of MNEC systems.
- Equip fire alarm companies to deploy sound reinforcement solutions.
- Bring the MNEC system into the scope of the sound reinforcement professional.
Both paths require training, and fundamental to each is the need for selecting and placing loudspeakers based on the room’s acoustics. There are software tools that can speed the process, but these require human decisions and expertise on the part of the user.
Once an intelligible system has been designed, there is a need for integration with the MNEC system. This requires knowledge of the code, and an understanding of the sound reinforcement hardware. In addition, the finished MNEC system must be tested to assure that the intelligibility objectives have been reached.
Most professionals attempt to glean the need information from various sources. But, this is research, and research requires time. There is also the danger that some important aspects are missed along the way. The best solution is to learn the fundamentals from people who are already doing it. Synergetic Audio Concepts, Inc. has created a training opportunity for the MNEC and sound reinforcement communities.
Emergency Communication Systems (ECS) Design and Deployment is a two-part event.
Part 1 – Design
presents a sound system design process that is based on the room’s acoustics, allowing the selection and placement of appropriate loudspeaker(s) to achieve on a target intelligibility score. Most importantly, the process considers the influence of background noise and room reverberation on the sound clarity. A systematic design approach allows the performance of the ECS to be evaluated at the drawing board, where design changes are easy to implement. Instructor – Pat Brown
Part 2 – Deployment
examines important changes to NFPA72, with emphasis on Chapter 24 – ECS and Annex D – Speech Intelligibility. Special topics include handling the Acoustically Distinguishable Space, Speech Intelligibility Testing, and the Fire Alarm/Paging System interface. World-renowned subject matter experts will present the topics, with ample time to answer specific questions regarding MNEC systems. Instructors – Wayne Moore, Larry Rietz, and Sander Van Wijngaarden.
Why spend years sorting through a sea of information, when you can get it all in one place, at one time? ECS Design and Deployment will dramatically reduce the learning curve and allow both fire alarm and sound reinforcement professionals to capitalize on code changes.
For more information, please chick here.