Theoretical and experimental study of sound absorption<br /> for thin fiber layers<br /> <br />
Journal Title: Science Paper Online - Year 2007, Vol 2, Issue 4
Abstract
Thin fiber layers such as fabrics and nonwovens have been used as the decorate materials in the room extensively. While it is also efficient at absorb sound and noise. Now, there are not special theory for thin fiber layers to explain the phenomenon that thin fiber layers absorb sound less when it is the cover fabric of sound absorber or rigid back, but has good sound absorption ability when it is hang as the curtains or have back cave behind it. That means there are probably another sound absorption mechanisms different from classical theory for thin fiber layers. Firstly, perforated resonance absorption theory is applied.It is found that the calculated resonance frequency is agreement with the first maximum sound absorption frequency obtained from the test. To get the exact result of sound absorption coefficient agree with the practice, the micro perforated sound absorption theory is applied also. Owning to this theory is not well agree with the testing result, a new idea is put forward that the vibration of materials must be considered as the absorption factor. The new theory which consider both the pore absorption and vibration absorption are more agreement with the testing results than classical theory. In addition and for most important, the new theory can explain the phenomenon that thin fiber layer absorb sound less when it is the cover fabric of sound absorber or rigid back, but more efficient when it is hung as the curtains or have back cave behind it.
Authors and Affiliations
Xin-an Zhang
Keywords
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