STUDY OF THE SOUND IMPEDANCE OF A WOODEN PANEL

Abstract

The development and production of effective sound-absorbing materials is an important direction in the construction industry. The results of studying features of the sound-absorbing properties of building structures, i. е., wooden panels, manufactured using CLT technology are presented. Sound insulation and sound absorption of CLT panels are based on the sound resistance. The sound pressure is formed by a frontal wave. The data were processed using the Laplace transform, the decomposition of sound into spectral components was carried out using the Fourier transform. Studies of wooden CLT panels with a cellular structure and given geometric parameters revealed that the acoustic impedance of the composite sound-absorbing CLT panel is higher than that of the massive CLT panel. Moreover, there is a difference in the sound resistance in the opposite direction of sound passage relative to the internal parabolic cavities. It is shown that the internal cavities act as instant resonators, whereas the enclosing elements of the CLT structure (walls, ceilings) with internal parabolic cavities can reduce the noise level by several times. Consequently, a single cavity ("sound pocket") formed by a paraboloid and a plane of a wooden lamella can be considered a module or an element of sound absorption. The results obtained can be used in the design of sound-absorbing materials using CLT composite sound-absorbing panels and modular design.