This paper describes a rapid algorithm for effective impedance in multilayered media. The layers are considered losses and have parallel interfaces. Recursive equations are developed and introduced that enable to calculate the effective impedance in compartments composed of any arbitrary number of layers. The calculations are carried out through an iterative process. Several important influence factors, that affect the multilayer acoustic absorber, are discussed. A simple algorithm is proposed, which allows to obtain qualitative knowledge of the behaviour of the frequency band with layer parameters. This technique can be used in different applications of ultrasonic techniques.
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