Controlling Noise in Classrooms

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

In the past, acoustical ceilings offered either good sound absorption to decrease unwanted sound levels, 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

  • Texas District Finishes Construction on New Middle School, Admin Building

    The Westwood Independent School District recently held a ribbon-cutting ceremony for the new Westwood Middle School and Administration Building in Palestine, Texas, according to a news release. The campus covers 106,000 square feet and has the capacity for 650 students in grades 6–8, and it will also play home to the district’s staff and administration.

  • New eBook Shares Guidelines on Building CTE Centers

    Career and Technical Education (CTE) curriculum and resources provider iCEV recently announced the publication of a new eBook sharing guidance and insights on building new CTE facilities, according to a news release.

  • California District Starts Construction on New Robotics Facility

    The Fremont Union High School District (FUHSD) near Silicon Valley, Calif., recently announced that construction has begun on a new Robotics Facility on the campus of Cupertino High School, according to a news release. The 14,500-square-foot facility will serve students at high schools across the entire district, providing purpose-built spaces for student creativity and collaboration.

  • Pittsburgh High School Upgrades Athletics Facilities’ Technology

    Plum Senior High School in Pittsburgh, Penn., recently partnered with South-Dakota-based Daktronics through the We’re All Mustangs Here Foundation to upgrade the technology in its athletics facilities, according to a news release. Daktronics designed, built, and installed new LED video displays and finished the project in time for the beginning of the 2025 high-school football season.

Digital Edition