Patent ID: 8275137

Claim:
A method of distortion reduction in a non-linear audio system, comprising the steps of: defining a non-linear system transfer function which relates a system electronic input signal with a system acoustic output and is valid over a range of input amplitude levels corresponding with at least a portion of a range of acoustic output sound pressure levels in which the system acoustic output is in a transition between non-saturated and saturated conditions in a medium in which the system acoustic output of the non-linear audio system is broadcast; creating a preprocessing transfer function which is the solved inverse of the non-linear system transfer function; and applying the preprocessing transfer function to the system electronic input signal to form a pre-processed electronic input signal, wherein the pre-processed electronic input signal is configured to provide a modified system acoustic output having a reduced level of harmonic distortion relative to the system acoustic output; wherein the preprocessing transfer function is of the form: y ⁡ ( t ) = [ E ⁡ ( t ) + u 2 3 ⁢ E ⁡ ( t ) 2 ] 1 / 2 wherein y(t) is the preprocessed electronic audio signal, E(t) is the input electronic audio signal, and u is an ultrasound pressure index value.