You may have a point, there. If the speakers are turned up loud I can't understand what is being said, because I hear the same thing from many speakers "at once". But the speed of sound is such that the sound from further speakers arrives later than the sound from nearer speakers, resulting in a dissonant mush of unintelligible sounds. With a lower volume, I won't hear the message from the further speakers, meaning that the message will be more intelligible.