The prediction of sound fields into a hard-backed layer sound absorption material

摘要

The current study focuses on the problem of sound transmission and reflection from arnhard-backed layer sound absorption material. The sound fields can be expressed in anrnintegral form that is amenable to analytical and numerical analyses. A standard saddlernpoint analysis supplemented by the pole subtraction method is applied to evaluate thernintegral approximately. A uniform asymptotic solution has been obtained for the soundrnfield into the hard-backed layer porous materials. The validity of these asymptoticrnformulas is confirmed by comparing with the numerical results computed by a morernaccurate numerical evaluation of the integral. It is shown that the asymptotic solutionrnprovides a convenient means for rapid and accurate computations of sound fields abovernand below the hard-backed layer sound absorption material. Further analysis has beenrnprovided to explore the possibility of using the asymptotic formulas for characterizing thernacoustical properties of the hard-backed layer sound absorption materials by placing anrnarray of microphones above and within the sound absorption materials.