Study On Acoustical Characteristics In Wood-based Sound-absorbing Materials And Its Application

Wood-based material is one of the most important raw materials for constructing and decorating living environment, which is consistent with ecological, environmental and sustainable requirements. The researches on the properties of wood-based materials are not confined to its anatomical properties, chemical properties and physical properties, but also paied more attention to the environmental harmony and comfortableness in wood-based materials. Nowaday, the current research on indoor acoustic environment has become a hot issue, especially for the special location of sound quality requirements, it is necessary to make a special sound design. In addition, wood-based sound-absorption materials have already been widely applied for interior decorate, wood structure architecture and all kinds of acoustic environment-designed locations such as gymnasium, odeum, arts sudio center, etc. owning to present high-quality acoustic characteristics, graceful grain, economical and practical properties, as well as easy processing.Based on the theory on the acoustic basic concept, transmiting principles of sound, indoor acoustic characteristics etc., the studies on sound-absorbed mechanism, sound-absorbed frequency characteristics and affecting sound absorption factors have been carried out on wood-based materials. The resluts show that wood fiber board takes on the wider frequency band and higher sound-absorbing coefficient; the peak value of sound absorption coefficient in thin wood board generally ranges from 200 to 300 Hz and moves to low frequency with the increase of the density in thin wood board; Wood perforated sound absorption boards have better medium-low frequency sound absorption characteristics, present diferent sound absorption effects based on different frequency bands by changing the depth, diameter and area ratio in pore of the perforated board and also meet the requirements of the decoration. Meanwhile, the wider frequency-band sound absorption and the higher sound absorption coefficient could be obtained by changing the conditions of backside cavity in wood sound absorption structure.High-quality effect can be obtained by using the wood sound absorption materials to control the tone in gymnasium, lecture hall and arts studio center. It is found that the arrangement of sound absorption materails in auditorium should be selected to content the requirements in different auditorium based on the diferent sound absorption characteristics for sound absorption structure to diferent frequency. Because the sound wave reflect more frequently on auditorium backwall, stage backwall, ceiling and floor, which can easily lead to acoustic defects in auditorium architecture, but backwall is the easiest portion to generate echo in auditorium, therefor, sound absorption treatment should start with backwall, and then deal with the sidewall that is distant from sound source or along with peripheral area of ceiling. Bulky Coliseum game hall must require higher sound absorption characteristics in sound absorption materials and structures, owning to the less region could be dealt with absorption treatment in its large volume. And then obtain the optimal sound field effect in limited materials and space. Based on the data analysis of measure reverberation time concluded that reverberation design achieved the prospective effect, enhance sound definition and decrease background noise.Therefore, from the angle of multi-principles on wood environmental science, acoustics, materials science and architecture etc. to understand acoustics characteristics of various wood sound absorption materials comprehensively, it is the important significant for wood-based materials to be used as controlling the tone in auditorium.