Integrated and Integrating Sound Absorbers

Abstract

The first three chapters of this compendium on applied acoustics describe the acute need for sound damping measures for machines, plants and buildings, pointing out the special low-frequency problem. The following Chaps. 4–9 present an up-to-date overview of different effects and designs of state-of-the-art as well as some novel marketable airborne sound absorbers, focusing on classifying and describing the physical damping mechanisms, which differ greatly in detail. Table 10.1 displays once more the most important ten absorber families and their characteristic frequency ranges, in which their absorption is able to develop particularly well. However, this does not mean that, for example, reactive membrane absorbers or panel absorbers with correspondingly little mass cannot be designed as silencer splitters in ducts for frequencies at about 500 Hz (see Figs. 13.25 and 13.26) or even in the kHz range (see Figs. 13.38 and 13.39) and passive materials with correspondingly larger depths as “bass traps” e.g. in music studios or class rooms for frequencies down to far below 100 Hz, (see Everest, The master handbook of acoustics, 1994) or Sect. 10.3.