Definitions for "Speech intelligibility"
How well you can understand what is being said. Though you may "hear" the sound, you may not understand it (and it's useless). Measurements can be taken to quantify what the intelligibility of a room and/or sound system are. see alcons
the intelligibility of speech (usually measured in the presence of noise or distortion)
The ability of a listener to hear and correctly interpret verbal messages. In a classroom with high ceilings and hard parallel surfaces such as glass and tile, speech intelligibility is a particular problem. Sound bounces off walls, ceilings and floors, distorting the teacher's instructions and interfering with students' ability to comprehend. Centers between 250 and 4000k.