The present invention provides a technique for interconnecting two or more substrates, in which the interconnecting elements are mechanically compliant. The method includes determining which one of two or more demodulators is preferred for use in a given region of the time-frequency grid by evaluating detection statistics generated by the demodulators for the set of symbols. The method includes the steps of positioning the integrated completion tool in the wellbore, detonating the explosive charge and packing the screen-casing annulus with a material. This is produced by a simplified equivalent circuit diagram from which the corresponding acoustic variables can be obtained. An element isolation dielectric region 14 is provided over the substrate 11.