Patent ID: 9171534
Filing Date: 2015-10-27
Classification: G10H

Abstract:
1. A method for artificially reproducing an output acoustic signal of a non-linear time invariant system using a data processing device, comprising the steps of: inserting an input acoustic signal of exponential sine sweep type into said non-linear time invariant system; acquiring an output acoustic signal of said non-linear time invariant system corresponding to said input acoustic signal; obtaining a mathematical function that characterizes said non-linear time invariant system on the basis of said output acoustic signal, said mathematical function being calculated assuming that said output acoustic signal is obtained by means of a Volterra series expansion of said input acoustic signal; applying said mathematical function to a further acoustic signal to obtain a still further acoustic signal that reproduces the output acoustic signal that would be obtained from said non-linear time invariant system if it were driven by said further acoustic signal; executing a convolution of said output acoustic signal, expressed as a Volterra series expansion of said input acoustic signal, with the inverse of said input acoustic signal; calculating the Fourier transform of said convolution; and executing the inverse convolution of said Fourier transform and applying corrective FIR filters to each term of said inverse convolution, said FIR filters being calculated by means of the Nelson-Kirkeby method.