Resources | Acoustical Glossary & Sustainability

Acoustical Terms Glossary

Key concepts used when specifying ceiling and wall systems. Click a term to expand.

Absorption

When sound waves contact a room surface such as a ceiling, wall or floor, a portion of the sound energy is reflected back into the room, and the rest is considered to be absorbed — primarily by conversion into heat due to friction within a porous material, or by vibration of a solid material.

Acoustical Material

Any material that affects the sound level or direction of travel of a sound wave. Some acoustical materials are specifically characterized as sound absorbers, sound reflectors, or as barriers to sound passage.

Ambient Noise

The lowest background noise level in a space.

Ceiling Attenuation Class (CAC)

A measure for rating the performance of a ceiling system as a barrier to airborne sound transmission through a common plenum between adjacent closed spaces such as offices. A ceiling system with a CAC < 25 is considered low performance, whereas one with CAC > 35 is high performance.

Frequency

The repetition rate of a sound wave measured in cycles per second, usually expressed in Hertz (Hz). The audible frequency range for normal hearing individuals spans from 20 Hz to 20 kHz. Frequency is the characteristic of a sound that is perceived by a listener as “pitch.”

LEED

Leadership in Energy and Environmental Design — a green building certification system developed by the U.S. Green Building Council (USGBC). LEED provides building owners and operators with a framework for identifying and implementing practical and measurable green building design, construction, operations and maintenance solutions.

NRC (Noise Reduction Coefficient)

The average sound absorption coefficient of a material at the four main frequencies of 250, 500, 1000 and 2000 Hz. NRC is a single-number rating that indicates the amount of sound energy absorbed upon striking a particular surface. An NRC of 0 indicates perfect reflection; an NRC of 1 indicates perfect absorption.

Sustainability & Recycling

Barrett-Homes is a member of the Armstrong Certified Recycler Network. We help divert ceiling tiles from landfills, supporting circular-economy practices and contributing to LEED credits for your projects.

When specifying systems, we can discuss recycled content, end-of-life recycling pathways, and other environmental product attributes that matter to owners and sustainability consultants.

Armstrong Certified Recycler Network member
Support for LEED and other green building goals
Responsible material selection and waste reduction

Practical Guidance

A few points we share frequently with design and construction teams.

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Match Performance to Use

Specify NRC and CAC based on the actual room function — open office, classroom, patient room, or corridor — rather than a one-size-fits-all approach.

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Coordinate Early with Lighting & MEP

Integrated systems (TechZone, linear metal with lighting, stretch with backlighting) work best when ceiling, lighting and mechanical teams collaborate from the start.

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Allow for Access & Maintenance

Consider future access needs for above-ceiling systems when selecting edge details, panel sizes and suspension types.