Adam Pilch

Sound absorption of wood-based materials

Abstract From modern buildings to public spaces are made of concrete, steel, and glass. These materials increase propagation of sound and the reverberation time. Therefore, furniture should be good sound absorbers in such places. The objective of this study was to ascertain acoustic properties of wood-based materials by determining normal acoustic impedance on the surface and sound absorption coefficients. Experiments were carried out on 17 types of wood-based materials commonly employed in furniture design and manufacture. Investigations were conducted based on the transfer-function method. It was demonstrated that for frequencies between 125 and 500 Hz, the highest capability of sound absorption was determined of low surface layer density and high porosity. Honeycomb panels with paper core absorbed better sounds in the range between 1 and 2 kHz. Panels of considerable external surface irregularities were characterized by the most favorable acoustic properties for the frequency of 4 kHz.

The influence of new material technology on acoustic treatment of modernized interiors

The paper deals with the problem of the acoustic treatment using modern material technology in the modernization of old interiors. On the example of an auditorium with approved acoustics, that was built in 1962 and is located at the Lviv Polytechnic, some important directions in handling this type of object was shown. The acoustic measurements of the room showed, that structures used in the 60s are acoustically proper, but planned renovation should be based on modern technologies.