Acoustic Simulations
Acoustic simulation experiments to analyze the design, configuration, quantity, and location of mycelium-based panels.
Form:
Matter: Mycelium
Fabrication:
Performance: Acoustics
Our perception of sound is dependent on our physical environment and is unique to the type of materials with which sound waves interact. Much of the sound that we hear arrives indirectly, meaning sound waves reflect off the many geometries of our environment before they reach our ears (Shinn-Cunningham, 2003). Thus, the placement and articulation of interior and exterior surfaces must be thoughtfully designed for acoustic purposes. Acoustic panels can be used as a mitigation strategy to help enhance the acoustic quality of a space. Acoustic panels also offer a large degree of customization, allowing for modifications depending on the design intent.
This research outlines the acoustic simulation and analysis of sound absorption panels made of mycelium-based composites. Given that mycelium-based composites are novel materials and lack comprehensive acoustical data, sound absorption tests are first performed to gather material-specific data on mycelium-based composites and their acoustic performance. This material-specific data is then used as an input for room acoustic simulations, using ray-tracing and image-source methods. The simulation results allow for an objective comparison between the design, configuration, quantity, and location of mycelium-based panels. This study intends to explore the use of acoustic simulations as an architectural strategy in the early phases of design.
Research Team: Natalie Walter and Benay Gürsoy
Publications:
Simulating Acoustic Performance of Mycelium-Based Sound Absorption Panels
Year: 2023
Simulation Tools
Simulation Set-Up
Pachyderm was selected to run computer simulations and acoustical analysis. Pachyderm is an open-source acoustic simulation plugin for Rhino and Grasshopper that combines ray-tracing and image-source methods for auralization and analysis. It uses the geometric surfaces defined in Rhino combined with material data inputs to analyze acoustic parameters such as reverberation time, sound clarity, sound pressure level, speech transmission index, and others.
The comparative parameter for acoustic analysis is reverberation time. Reverberation time refers to the amount of time it takes for the sound pressure level to decrease 60 dB once the sound source stops producing sound (Adams, 2016). This metric is directly related to the volume of enclosed space and the absorption coefficients of the surface materials.
The environment of the simulation experiment consists of a shoebox geometry, panels attached to an interior wall, a sound source, and a sound receiver. The shoebox geometry defined is 18’ x 14’ x 10’ in length, width, and height. The panels have a total surface area of 60 ft2 on the short end of the room.
Materials are assigned to each interior wall, floor, and ceiling within Pachyderm’s material editor. The sound absorption coefficients of the best performing material derived from these acoustic tests are assigned to the mycelium panels. Drywall is assumed for the interior wall finishes, and the sound absorption coefficients are inputted reflecting 1/2″ plasterboard paneling on studs. The ceiling is assumed to be a commercial absorption ceiling, common in educational facilities. The sound absorption coefficients used are from Armstrong® Ceilings, specifically the Fine Fissured™ School Zone® ceiling panel (Armstrong Ceilings, n.d.). The sound source is a geodesic source assigned to a point, and the sound receiver is defined as a stationary receiver assigned to a separate point.
