Close Solution to Acoustic Illusion in Layered Media.

A close solution to acoustic illusion, caused by layered acoustical concentrator, has been investigated in-depth theoretical analysis using acoustic wave scattering theory. Based on this theory, a precise expansion for the scattered pressure field in each layer has been calculated, which by comparing this expansion with scattered field expansion of a bare cylinder, the illusion perception has been illustrated clearly. To show more clear illusion perception, an angular scattering cross section has been provided for bare and layered media. The size and constitute parameters of bare and layered media have been calculated using both transformation acoustics theory and effective medium theory. It is noteworthy that the concentration effect of layered concentrator has been introduced before, but no close solution to illusion perception has ever been provided. [ABSTRACT FROM AUTHOR]