WOOD RESEARCH Volume 61, Number 1, 2016
Francesco Negro, Corrado Cremonini, Roberto Zanuttini, and Marco Fringuellino

Development of framed poplar plywood for acoustic improvement

Acoustic is a fundamental topic in large environments often characterized by poor sound quality such as dining rooms or open space offices. The paper reports the development and testing of sound absorbing poplar plywood for the acoustic improvement of such spaces; prototypes were designed aiming at acoustic performance and lightness, as an alternative to other acoustic woodbased panels currently on the market. The experimentation ranged from the testing of small specimens to the validation of prototypes in end-use dimensions. Developed panels achieved high sound absorption peaks in the low frequency range (sound absorption coefficient α = 0.80 at frequency of 315 Hz). Prototypes installed on the walls of a dining room reduced significantly its reverberation time (RT60); room users, investigated by a questionnaire, perceived a high acoustic improvement. On the whole the designed products resulted effective sound absorbers; their industrialization can represent a valuable niche for poplar plywood producers.

WOOD RESEARCH Volume 63, Number 4, 2018
Limin Peng, Meihong Liu, Dong Wang, and Boqi Song

Sound absorption properties of wooden perforated plates

Wooden perforated plates are used to control noise and optimize the indoor sound environment. In the paper, the effects of structure factors on the sound absorption properties, such as the absorption peak, resonant frequencies, and frequency bandwidth, were analyzed using the impedance tube transfer function method and SAS (Data analysis software) significant analysis. Experimental results showed that with the thickness of the medium density fiberboard (MDF) perforated plate increasing from 10 to 20 mm, the resonance absorption frequency shifts to the lower frequency. The depth of hole increased, the absorption peak reinforced. With the pore size increased, the resonance absorption frequency reduced and meanwhile the resonance peak absorption coefficient shrunk. The resonance frequency moves toward the high frequency direction and the sound absorption coefficient decreased when the perforation rate was increased from 3.14% to 7.07%. After increasing the air gap thickness from 25 to 100 mm, the resonance absorption frequency reduced and the sound absorption bandwidth remained relatively constant as the acoustic impedance of the MDF perforated plate did not vary in spite of the variation in the air gap thickness. But the absorption coefficient decreased. This paper may provide a certain theoretical basis for wooden perforated plate design and research.

WOOD RESEARCH Volume 65, Number 6, 2020
Juan Miguel Barrigón Morillas, Rubén Maderuelo-Sanz, Pedro Atanasio-Moraga, Valentín Gómez Escobar, Rosendo Vílchez-Gómez, Guillermo Rey Gozalo, and David Montes González

Short note: Virgin cork, a possible environmentally friendly by-product of the cork with acoustic properties for its use inside dwellings?

This paper is a first study to evaluate the acoustical performance of virgin cork environmentally friendly by-product of the cork that can be used inside dwellings. To obtain the acoustical performance of the virgin cork, previously, it was properly treated and flattened into slabs, and later compared to commercial rock wool. The results obtained showed that this material, specially treated and added in some building system, could show good acoustic properties with a certain broadband absorption spectrum.