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Environmental Acoustics

design means feeling better,

working better and healing better in any setting.

Our physical surroundings in any given setting contribute to a space’s acoustics. The environment can be made

pleasant with wanted sounds, or it can be polluted by unnecessary and unpleasant noise. With proper Environmental


design, sounds can be controlled to ensure a space suits the way it is commonly used – whether that is

concentration, collaboration or rest.

The CAC is a measure

of how well a ceiling

panel blocks sound

transmission when

traveling from one room

into a ceiling plenum with

no wall above and down

into another room with

the same type of ceiling

(measured according to

ASTM E1414).

Noise reduction occurs

when materials and

objects convert sound into

heat energy. Reflected

sound always loses

some energy, but the

amount greatly depends

on the material of that

surface. This is measured

as the Noise Reduction

Coefficient (NRC). An

NRC of 0 indicates

perfect reflection; an

NRC of 1 indicates perfect

absorption (measured

according to ASTM


This is a measure for

rating the speech privacy

performance of a ceiling

system in an open plan

environment where

the space is divided by

half-height, cubicle-style

walls. AC measures how

much sound is reflected

off the ceiling between

the two divided, adjacent


<150 = Poor Performance

>200 = High Performance

(Measured according to

ASTM E1110.)

Noise Reduction

Coefficient (NRC)


Class (AC)

Ceiling Attenuation

Class (CAC)

The graphics below explain the key factors that affect Environmental Acoustics

design and how they are measured. The right blend of ceiling products can ensure

these acoustical properties best accommodate a space’s intended usage.

Noise Reduction Coefficient (NRC), Ceiling Attenuation Class (CAC) and Articulation Class (AC)

are measured according to the American Society for Testing and Materials (ASTM) standards.


Sound Reflection

The reflection of sound can enhance

the quality and volume of speech and

music, as well as noise.

Other factors that affect

a room’s acoustics:

Reverberation Time

After sound is ended at the source, it

continues to reflect off surfaces until

it is completely absorbed. This effect,

termed reverberation, influences

speech intelligibility, enjoyment of

music and noisiness of a room.