Prediction of the absorption exponent in rectangular enclosures with a single absorbent boundary

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• 作者：Ning Han ; Cheuk Ming Mak
• 关键词：Enclosures with a single absorbent boundary ; Absorption exponent
• 刊名：Applied Acoustics
• 出版年：2009
• 出版时间：February 2009
• 年：2009
• 卷：70
• 期：2
• 页码：297-299
• 全文大小：194 K

文摘

It is known that the classical theory of room acoustics cannot be strictly applied to the study of the sound field in a rectangular enclosure with only five boundaries (i.e., with a single absorbent boundary), as the sound field in the enclosure is not diffuse. A theoretical method is developed for the prediction of the absorption exponent in a rectangular enclosure with a single absorbent boundary, and the absorption exponent is used to describe the exponential decay of the sound energy. The method is based on the radiosity-based theoretical/computer model and is used for diffusely reflecting boundaries. The predicted absorption exponent is compared with the Kuttruff values and the simulation results from Monte-Carlo computations. It is found that the predicted absorption exponent of the proposed method shows better agreement with the simulation results from Monte-Carlo computations than the Kuttruff values. With the more accurately predicted absorption exponent, the slope of the energy decay curve and other acoustic parameters in an enclosure with a single absorbent boundary can be obtained accurately.