Achieving audibility and intelligibility in the classroom
January 11, 2013
By Dan Ostergren, Au.D.
Is “speaking up” good enough?
One of the great ironies of teaching is that many teachers probably think that as long as they speak loudly enough, every student in their class will not only hear them, but also understand them.
There’s a certain logic in that kind of thinking, because we often think that turning up the volume will enable everyone to hear us. But do students in a large classroom really understand every word a teacher is saying? I think, often, they do not.
Battling noise competition
The challenges of a classroom from an audio perspective are large. There may be many students nearby who are shuffling around in their seats or rustling paper. There may be extraneous noise from a classroom HVAC system, or a nearby band room, or playground — in other words, external noise competition for the teacher’s voice.
Then there are nuances such as the teacher turning to write on a board, so her voice is directed away from the students. All of these factors can compromise the intelligibility for some students of what a teacher is saying.
How to meet the challenges
The real challenge in classroom teaching is not merely that students can “hear” that a teacher speaking, but that they understand every word.
Research has shown us that while students spent 75% of their day listening, nearly all classrooms– 97% – fail to meet the acoustical standard for a good learning environment.
In unamplified classrooms, proximity to the teacher plays a significant role in how well students hear. Research has shown that students seated just 6 feet away show a 17% loss in critical speech recognition. Move farther away – say to the back of the classroom – and students may miss up to 30% of what their teacher says.
A seminal body of research – Improving Classroom Acoustics (ICA) Studies – found 95% of students said instructional audio made it easier to hear their teacher and helped them listen better.
Learn more about how instructional audio can help improve audibility and intelligibility in the classroom:
Case Study: An assessment of the efficacy of a classroom audio distribution system using Language Environment Analysis (LENA)
Case Study: Lancaster School District discovers positive correlation between student engagement and classroom audio system
How instructional audio can help overcome listening challenges
Article: Ears: The doorway to the brain
Article: Why classroom acoustics matter
Infographic: 6 reasons a classroom audio system benefits teachers and students