Beyond routine announcements, what specific operational requirement must a public address (PA) system fulfill to be considered effective for emergency messaging in a large outdoor event?

For a public address system to be considered effective for emergency messaging in a large outdoor event, it must primarily ensure exceptional message intelligibility and comprehensive coverage. Intelligibility means that emergency instructions are not merely audible but are clearly understood by all listeners, even amidst background noise or crowd panic, a requirement achieved through optimal acoustic design, appropriate frequency response, and minimal audio distortion. Comprehensive coverage mandates that the message reaches every person within the designated event area with uniform sound pressure levels, eliminating dead zones and preventing areas of excessive....