Skip to main content
Add as a preferred source on Google

Controlling Noise In Classrooms

Acoustical performance is vital ceiling selection criteria for classrooms. The reason: students must be able to hear and understand their teacher if they are to learn.

In the past, acoustical ceilings offered either good sound absorption to decrease unwanted sound levels in a classroom, or good ceiling attenuation to block unwanted sound intrusion from adjacent classrooms or corridors, but not both absorption and blocking in the same ceiling.

Now, the science behind the ceiling is able to offer a new generation of acoustical ceiling panels that provide an ideal combination of sound absorption as denoted by their Noise Reduction Coefficient (NRC) and sound blocking as denoted by their Ceiling Attenuation Class (CAC) in the same panel.

The NRC indicates the ability of a ceiling to absorb sound. It is expressed as a number between 0.00 and 1.00, and indicates the percentage of sound it absorbs. An NRC of 0.60 means a ceiling absorbs 60 percent of the sound that strikes it. A ceiling with an NRC less than 0.60 is considered low-performance, one with an NRC of 0.70 or greater, high-performance.

The CAC indicates the ability of a ceiling to block sound in one space from passing up into the plenum and transmitting back down into an adjacent space that shares the same plenum. The higher the number, the better the ceiling acts as a sound barrier.

A ceiling with a CAC less than 25 is considered low-performance, one with a CAC of 35 or greater, high-performance.

Regardless of whether it’s new construction or renovation, the best solution for both reducing the level of sound in a classroom and limiting sound intrusion into it is an acoustical ceiling panel that combines an NRC of 0.70 or greater and a CAC of 35 or greater.

This article originally appeared in the issue of .

About the Author

Sean Browne is principal scientist - Global Acoustics for Armstrong Ceilings.

Featured

  • TCU Marks Campus Expansion Milestone

    Texas Christian University in Fort Worth, Texas, recently held a topping-out ceremony to mark progress on a major campus expansion effort including four new residential facilities and a five-story parking garage, according to a news release.

  • Rethinking K-12 Schools as a Continuous Learning Experience

    Most students move through three or more separate facilities during their K-12 journey, yet the built environments they encounter at each stage have traditionally been designed in isolation, with little continuity in spatial language, learning philosophy, or physical resources. Each new school is a reset with different layouts, learning models, expectations, and ways of moving through a building. The next generation of school design is making the case that the first day of kindergarten and the last day of high school can and should feel connected through common support systems and infrastructure in the physical environment.

  • Q&A: How to Prevent Kitchen Grease Fires in Commercial Kitchens

    School cafeterias and university dining halls serve thousands of meals daily, relying on high-heat equipment like fryers, grills, and ovens. While these operations keep students fed, they also generate significant grease-laden vapors. Without proper controls, this grease becomes a silent fire threat. As a certified exhaust cleaning specialist and business coach who has helped hundreds of institutional facilities achieve NFPA 96 compliance, I emphasize that proactive grease management isn’t optional; it’s a core fire/life safety practice.

  • Designing Third Spaces That Do What AI Can't

    In 2026, education is evolving faster than ever. With AI reshaping everything from lesson planning to personalized instruction, schools and universities are turning their attention to what AI can’t replicate: spaces that foster collaboration, community, and creativity.