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Software for the acoustical design of acceptable indoor environments
COPE
COPE
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-
Calc
Calc
Open-Plan Office Design for Speech Privacy
John S. Bradley
COPE
COPE
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Calc:
Calc:
• Product of COPE project:
Cost-effective Open-Plan Environments.
• The Problem: Difficult to achieve adequate speech privacy in open-plan offices without full height walls.
• COPE-Calc allows the user to optimise designs and compare multiple designs.
• Numerical indicators of speech privacy are
calculated and audio simulations are provided to help understand the significance of the results.
The Goal of Open Office
The Goal of Open Office
Acoustical Design
Acoustical Design
Open
Open
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Plan Offices:
Plan Offices:
In 1970s proliferation of open-plan offices led to understanding of key design requirements and related ASTM standards.
Speech Privacy:
Speech Privacy:
• Speech privacy: providing conditions where unwanted speech is less intelligible and less disturbing.
• Speech privacy is related to the level of unwanted speech sounds relative to ambient noise levels.
• That is, it is related to (S/N) signal-to-noise ratios.
• We need to calculate the expected level of speech from an adjacent workstation and estimate the
level of ambient noise to calculate S/N ratios.
• Calculate: AI (Articulation Index) and
Propagation between Workstations:
Propagation between Workstations:
-The workstation panels should block the direct sound path. -The ceiling reflection and
diffraction over the common panel are the most important paths.
-There are also paths involving more
Calculations:
Calculations:
•
• Reflected paths calculated using Reflected paths calculated using image sourcesimage sources technique.
technique.
•
• Diffracted path calculated using Diffracted path calculated using Maekawa’sMaekawa’s empricalemprical results.
results.
•
• DatabaseDatabase of absorption coefficients of ceiling tiles,of absorption coefficients of ceiling tiles, workstation panels and carpet as well as sound
workstation panels and carpet as well as sound
transmission characteristics of workstation panels.
transmission characteristics of workstation panels.
•
• DatabaseDatabase also includes speech source levels and ambientalso includes speech source levels and ambient noise levels.
Open
Open
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-
plan office design criteria:
plan office design criteria:
•
• SII SII ≤≤ 0.20 (or AI 0.20 (or AI ≤≤ 0.15)0.15)
•
More Information:
More Information:
Download COPE
Download COPE--Calc free at: Calc free at: http://
Transport Canada,
Department of National Defence
Software to Design
Software to Design
Building Sound Insulation for
Building Sound Insulation for
Acceptable Indoor Environments
Acceptable Indoor Environments
John Bradley
Funded by: Department of National Defence National Research Council Transport Canada
IBANA Project
Insulating Buildings Against Noise from Aircraft
IBANA Project
Insulating Buildings Against Noise from Aircraft
• Buildings near airports can be exposed to significant levels of
aircraft noise.
• Although better to build elsewhere, often the solution is to provide
improved sound insulation.
• IBANA project was intended to better understand how to do this. • IBANA-Calc software was a product of this project intended to help
make the design process more convenient, more understandable and to make comparisons of various designs possible.
Aircraft noise problems:
Aircraft noise problems:
Source: moving directional low frequencies Propagation: Multiple paths Transmission: angle of incidence multiple paths
IBANA Project Components:
IBANA Project Components:
•
Lab tests of sound insulation of
building envelope components.
•
Field tests of building sound
insulation.
•
Combining lab and field tests to
Lab Tests:
Lab Tests:
Upper Chamber Lower Chamber Test Frame 2"x4" 2"x4" 2"x4" } polystyrene insulation baffle Insulation depth Test frame •Unique N. American
data.
• Includes 50-5000 Hz.
• Walls, windows, roofs.
• Effects of vents.
Ottawa Airport Test House:
Ottawa Airport Test House:
3.66 m 4.27 m Door Window Window Window Window 1.22 m masking wall masking wall
Aircraft flight path
Room A Room B
Validation Tests:
Validation Tests:
Toronto
IBANA-Calc software:
http://irc.nrc-cnrc.gc.ca/ie/acoustics/walls/ibana_e.html
