@article {Kuhl:1960:1610-1928:264, title = "Der Einflu der Kanten auf die Sdwllabsorption poroser Materialien", journal = "Acta Acustica united with Acustica", parent_itemid = "infobike://dav/aaua", publishercode ="dav", year = "1960", volume = "10", number = "4", publication date ="1960-01-01T00:00:00", pages = "264-276", itemtype = "ARTICLE", issn = "1610-1928", url = "https://www.ingentaconnect.com/content/dav/aaua/1960/00000010/a00104s1/art00004", author = "Kuhl, W.", abstract = "A survey is given over various theoretical investigations concerning the increase of the absorption of sound due to diffraction at edges. Measurements of sound absorption of rock wool plates are reported and compared with calculations and measurements of other authors. With constant over-all surface area the size of single sections and thus also the edge length is varied to a great extent. The absorption coefficient is increasing from the lower limiting value (without diffraction) proportionally to the normalized edge length. For small surface areas an upper limiting value is reached, which for high impedance is eight times the relative conductance. Plotting the absorption coefficient versus edge length, it is seen that the shape of the resulting curve is the same for all measurements and calculations.The absorption coefficient is essentially increased, if small samples are placed in corners or edges of the room. The edge effect is reduced, if the edges of the absorbing sheets are lined with broad planks or if the material is arranged tesselated.", }