Angle-Dependent Absorption of Sound on Porous Materials

Cucharero, Jose; Hänninen, Tuomas; Lokki, Tapio

doi:10.3390/acoustics2040041

Cited by 16 publications

(10 citation statements)

References 20 publications

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“…The measurement methods are incorporated into the system, following the ISO 10534‐2:2001 standards 38 . Besides, reverberation time in room, 39 floor impact sound pressure level, 40 the in‐situ approach, 41 and angle‐dependent sound absorption coefficients 42 are some known methods that could be useful in measuring sound performance on a building scale. Compared with other available methods, measuring the SAC of the cross‐sectional surface of the wood with an impedance tube is inexpensive and straightforward.…”

Section: Methodsmentioning

confidence: 99%

Effects of ammonium persulfate on coconut wood (Cocos nucifera L.) cellulose, hemicellulose, and lignin polymers: Improved sound absorption capacity

Kolya

Jang

Hashitsume

et al. 2022

J of Applied Polymer Sci

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The rational design of sound absorption boards made of wood materials is an attractive field of research. This article describes a simple and low‐cost ammonium persulfate treatment on coconut wood cell walls (Cocos nucifera L.). Reaction parameters such as concentration of reactant and reaction time were optimized. The results of different instrumental characterization such as X‐ray photoelectron spectroscopy, X‐ray diffraction, attenuated total reflectance–Fourier transforms infrared spectroscopy, and scanning electron microscope supports the chemical alterations of the wood cell wall. The quantitative analysis of hemicellulose, cellulose, and lignin was performed. The significant changes in cell‐walls enhanced average sound absorption coefficient at each frequency range: 60.4% at 500–1000 Hz (t = −10.593 and p < 0.001), 80.8% at 1000–2000 Hz (t = −4.798 and p < 0.001), 96.2% at 2000–4000 Hz (t = −58.527 and p < 0.001) and 83.0% at 500–64000 Hz (t = −51.261 and p < 0.001). It is due to the increment of gas permeability (288.3%, p = <0.001). These results could be beneficial for new research on wood‐based sound absorption materials to regulate the acoustic environment in houses.

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Section: Methodsmentioning

confidence: 99%

Effects of ammonium persulfate on coconut wood (Cocos nucifera L.) cellulose, hemicellulose, and lignin polymers: Improved sound absorption capacity

Kolya

Jang

Hashitsume

et al. 2022

J of Applied Polymer Sci

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“…While both methods are well-defined ways to measure the material absorption, they do not capture directional absorption properties of the material. Currently, there are also new yet unstandardized methods that also allow capturing the directional properties of the material [60].…”

Section: Laboratory Measurementsmentioning

confidence: 99%

Sound rendering with early reflections extracted from a measured spatial room impulse response

Puomio

Pihlajakuja

Lokki

2021

2021 Immersive and 3D Audio: From Architecture to Automotive (I3DA)

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There are a lot of colleagues that I grateful for the support and companionship. I thank Professor Jaakko Lehtinen for nudging me towards the academy and showing what can be achieved by thinking big; Tapani Pihlajakuja for breathing new life to my PhD; and Nils Meyer-Kahlen for reaching completely new heights of invention. I also thank coauthors Jukka Pätynen for introduction to research work and Raimundo Gonzalez for intriguing journeys inside and outside office hours. I am also grateful to all the colleagues and partners that helped me along the way: Benoit

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“…In most cases, sound-absorbing materials are measured in a reverberation chamber. In a study by Cucharero et al [ 16 ], the authors showed how angle-dependent absorption coefficients could be measured. The results were in good agreement with sound absorption coefficients and confirmed that materials have different attenuation behavior to sound waves coming from different directions.…”

Section: Introductionmentioning

confidence: 99%

Effect of 3D-Printed PLA Structure on Sound Reflection Properties

et al. 2022

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3D printing technique is currently one of the promising emerging technologies. It is used in many areas of human activity, including acoustic applications. This paper focuses on studying the sound reflection behavior of four different types of 3D-printed open-porous polylactic acid (PLA) material structures, namely cartesian, octagonal, rhomboid and starlit structures. Sound reflection properties were evaluated by means of the normal incidence sound reflection coefficient based on the transfer function method using an acoustic impedance tube. In this study, various factors affecting the sound reflection performance of the investigated PLA samples were evaluated. It can be concluded that the sound reflection behavior of the tested PLA specimens was strongly affected by different factors. It was influenced, not only by the type of 3D-printed open-porous material structure, but also by the excitation frequency, the total volume porosity, the specimen thickness, and the air gap size behind the tested specimen inside the acoustic impedance tube.

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Angle-Dependent Absorption of Sound on Porous Materials

Cited by 16 publications

References 20 publications

Effects of ammonium persulfate on coconut wood (Cocos nucifera L.) cellulose, hemicellulose, and lignin polymers: Improved sound absorption capacity

Effects of ammonium persulfate on coconut wood (Cocos nucifera L.) cellulose, hemicellulose, and lignin polymers: Improved sound absorption capacity

Sound rendering with early reflections extracted from a measured spatial room impulse response

Effect of 3D-Printed PLA Structure on Sound Reflection Properties

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