There’s nothing worse than having an unruly class of students that are difficult to control. The teacher ends up raising their voice which in turn adds to the noise of the room and the entire place descends into an environment where nobody learns anything, and the teacher goes home very stressed with a sore throat.
The answer to this problem is a soundfield system which is basically a sound reinforcement system whereby the teacher wears a microphone that is connected to a compact amplifier which in turn drives a couple of discrete loudspeakers. This little bit of extra help allows the teacher to maintain control over the class as they will always be heard.