The Science behind Classroom Audio

Classroom Audio Systems help all students hear the teacher at a normal speaking tone, despite where they are sitting in class. It is not about making the teacher’s voice louder. No matter how loud a teacher speaks without a classroom audio system, the kids in the back simply can’t hear as well as the kids in the front. That’s due to the Inverse Square Law, which says when the distance from the source of sound doubles, the intensity of the sound is reduced to a quarter of what it started as. Think of it like the siren on a police car. When it’s about 100 feet away, you can hear it about 140 decibels (dB). That’s louder than a rock concert! But as the siren moves to 200 feet away, its intensity is reduced to only 35dB—about a whisper.

Research shows that for students to understand, they need the teacher’s voice to be at least 15 decibels (dB) louder than any background noise. That’s perfect for the kids in the front—the average conversational voice is 65 dB, and average background noise is about 50 dB. But the kids in the back? Thanks to that pesky Inverse Square Law, the background noise for them will be 3 dB louder than the teacher. Expecting the whole class to hear the teacher from the front of the room is like trying to light an entire classroom with one really bright lightbulb at the front. No matter how bright the light is, the back of the room will still be dark, and some students won’t be able to see. It’s the same with sound. With Audio Enhancement’s Classroom Audio System, which evenly distributes the teacher’s natural speaking voice with the use of a microphone, every student in the room can not only hear, but truly listen and understand as if he or she were at the front of the room.