SYDNEY TAYLOR
Focus: Acoustics
Application Potential
The application of strategic acoustical design will greatly impact the the design solution because sound impacts a students ability to learn. As a whole, the design emphasizes flexibility, independence, collaboration, and vertical learning to improve the learning experience by accommodating for different teaching and learning styles. These aspects of the design have the potential to lead to increased noise levels. Excessive negatively impact concentration, stress, and learning. With proper acoustical design, this problem can be significantly minimized. The use of materials with high NRC and CAC values and soft surfaces will decrease reverberation time and reduce excessive noise.
fast facts
Reverberation
Reverberation time is how long sound resonates in a space. According to ANSI Standard S12.60, reverberation time should not exceed .60 seconds for classrooms less than 10,000 cubic feet and .70 seconds for classrooms over 100,000 cubic feet. Longer reverberation times cause sound distortion leading to miscommunication.
Interior noise sources from other spaces and machinery should not exceed 35dBA
Exterior noise sources should not exceed 35dBA
Students do not understand 25-30% of what is said in the classroom due to noise.
A typical conversation averages at approximately 65 dBA.
TERMS TO kNOW
CAC
Ceiling Attenuation Class; a measurement of a ceiling systems' ability to block sound transmissions within a common plenum space
NRC
Noise Reduction Coefficient; rates a product's ability to absorb sound on a scale of 0-1
Noise Pollution
Unwanted disrupting noise that interferes with daily activities, such as learning
Decibels
A unit that measures the intensity of sound
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Sources: Armstrong Ceilings; Dockrell
Design Criteria
Materials
Use materials with high NRC and CAC to reduce reverberation time
Install double pane glass windows to reduce
exterior noise pollution
windows
surfaces
Use furniture with soft surfaces to absorb sound
Install an acoustical barrier along Government St. to reduce traffic noise
Exterior wall
Focus Solution
By applying acoustical wall tiles, acoustical ceiling tiles with high NRC and CAC values, soft surfaces, double pane windows, and an exterior acoustical wall along Government Street, the reverberation rate is optimized, as proven my Armstrong Ceilings' Reverberation Time Graph. The acoustical wall tiles are used in the collaboration spaces because they are large open rooms that would normally have a higher level of noise and need more acoustical properties to control sound. The collaborative core and the class rooms use soft surfaces such as carpet tile and cushioned furniture. Some furniture selections even have acoustical panels to block out sound. Ceiling tiles with high NRC and CAC values will significantly reduce sound travel within the plenum space. To reduce exterior noise pollution, a brick wall running along Government Street blocks noise of traffic, and the double pane exterior windows allow for an acoustically sound envelope.
Armstrong Reverberation Time Graph: Classroom
This graph shows that the typical classroom has an ideal reverberation time with the application of Armstrong Lyra ceiling tiles and other soft surfaces. At a frequency of 1,000Hz, the ideal reverberation time is 0.4-0.6 seconds and the existing reverberation time is .42 seconds.
Source: Armstrong Ceilings.
Armstrong Reverberation Time Graph: Collaborative Core
This graph shows that the typical Collaborative Core has an ideal reverberation time with the application of Xorel Artform acoustical wall tiles, Optima L Canopy, and other soft surfaces. At a frequency of 1,000 Hz, the ideal reverberation time is 0.5-1.5 seconds and the existing reverberation time is .55 seconds.
Source: Armstrong Ceilings.