Intelligibility - A loud sound system means nothing if you can't understand what is being said. How many times have you heard a band and you can't separate the words from the background? Worse yet a guest speaker?
In a recent post by Audio Precision they offer new software to measure intelligibility.
"Measuring speech intelligibility is an important capability for engineers designing and validating a wide range of communication systems, products and components, especially those related to public safety (e.g., police, fire, emergency) where intelligibility is critically important."
I equate good sound to that of a flashlight beam. If you are in a totally dark room with a flashlight, anything in the "beam" of light will be clearly visible. Anything else in the dark room will have a "glow" from the flashlight but with diminished clarity.
A sound system should deliver direct sound to every audience member. If not, some of your audience will be in the "glow" of the sound system, but not able to detect the difference between "sitting" and something much worse.
Importance of speech intelligibility - Audio Precision
The purpose of communication systems is to transmit information via speech. As such, the intelligibility—or comprehensibility—of the transmitted speech is of utmost importance. One of the more precise definitions of intelligibility is the proportion of speech items (words and/or speech sounds) uttered by a talker, and sent via a communication system, that can be recognized by the listener.
Don't accept a sound system that only delivers noise. Insist on quality, direct sound to every audience member. Not just filling the room with noise.
Professional sound systems are "tuned" by experts, many using software similar to what Audio Precision offers.
Meeting planners can not expect the typical in-house-AV supplier to understand any of this. During planning, insist you are able to test, with your ears, every section of the audience's ability to understand the content.
Insist every member of your audience can see and hear. #AudienceAdvocate - Google it