Rosslyn, VA, September 11, 2008: The National Electrical Manufacturers Association (NEMA) has published SB 50-2008 Emergency Communications Audio Intelligibility Applications Guide.  

According to Jeff Brooks, a member of the Signaling Protection and Communication Section that prepared this guide, it provides an overview of issues and general recommendations.

“This publication assists specifiers, emergency voice system designers, and authorities having jurisdiction who are not experts in acoustics with the concepts used to enhance intelligibility and it provides a better understanding of the factors affecting the intelligibility of these systems,” Brooks said.

“In the past, the fire alarm industry primarily focused concern on audibility requirements, assuming that if the sound was loud enough it would be sufficiently intelligible. Today, emergency voice communications systems are extensively used to provide building occupants information and instructions during all types of building emergencies. Consequently, intelligibility of these paging systems has become a vital concern. These messages contain essential safety information that must be clearly understood by the building occupants.”

This is a new NEMA publication that draws on Tyco’s Fire Alarm Audio Applications Guide as its primary source material.

The contents and scope of may be viewed, and a hard copy or electronic copy purchased for $66, by visiting NEMA’s website, or by contacting IHS at 800-854-7179 (within the U.S.), 303-397-7956 (international), 303-397-2740 (fax), or on the Web.