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ACOUSTIC PROPERTIES
Material
Wood has inherent acoustic properties, such as low resonance, which can contribute to better sound absorption. (Salenikovich and Fröhlich 1969)
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Sound Absorption
The acoustic panel is designed to be mounted indoors to provide sound absorption instead of sound insulation. BS EN ISO 11654:1997ìAcoustics - Sound absorbers for use in buildings - Rating of sound absorptionî: This standard provides a rating system for the sound absorption of various materials used in buildings, including acoustic panels. It defines the sound absorption class (A to E) based on the sound absorption coefficients. (BS EN ISO 11654:1997)
Timber has a moderate level of sound absorption which is lower than acoustic foams or mineral wool. However, designing the surface into a spiral and spiky pattern can allow sound waves to penetrate the timber mass and dissipate better.
I have created a small enclosed space with a wooden shelf and felt, with one side of it being the back side of the panel, which is a smooth MDF texture. I then play a tone (440Hz) within the space and measure the decibels (dB) of the internal space. The experiment is then repeated with the textured side.
The result from the sound level meter shows an even decrease in the whole range of frequency from 73dB to 66 dB.
The panel is often perforated or textured to increase sound absorption. In this design, triangle bits are staggered in a herringbone pattern to absorb and dampen sound waves.
Form Application
A series of panels can be mounted at auditoriums, theaters, recording studios, offices, and residential spaces, to enhance sound quality and reduce echo or reverberation.
Room Reverberation
Reverberation time (RT) measures how long sound persists in space after the sound source has stopped. With sound-absorbing materials such as timber, it will speed up the decaying process of sound. Adding acoustic panels enhances the clarity of sound, especially speech. (Hetreed, Ross, and Baden-Powell 2017)
An RT test requires an octave-band analyser, a calibrated loudspeaker and an empty enclosed room. If I were to test the panel, I would also have to fabricate a series of these compoenent to produce a significant effect.
