A process for modifying an input signal, which is an audio signal, comprising: the splitting of the input signal into at least a first input part and a second input part; the amplification (3, 4) of at least the first input part with a linear gain to create a first output part and the amplification of at least the second input part of the input signal to create a second output part, wherein the amplification of the second input part comprises a nonlinear amplification; and summing the first output part and the second output part in order to provide an output signal, wherein the amplification characteristic of the output signal in relation to the input signal comprises a first amplitude range with an essentially linear first gain and a second amplitude range comprising a nonlinear gain covering lower amplitudes than the first amplitude range, whereby the nonlinear gain of the second amplitude range is always higher than or as high as the linear first gain of the first amplitude range; wherein an instant amplitude signal correlated to the second input part is generated and used for controlling the gain of the nonlinear amplification of the second input part, the instant amplitude signal being generated by producing a complex signal and then calculating the square root of the sum of the squares of the real and imaginary components of the complex signal, wherein the imaginary component of the complex signal represents a Hilbert transformation of the real component of the complex signal, and wherein the real and imaginary components of the complex signal both have the same amplitude spectrum as the second input part; wherein the first amplitude range begins at a threshold amplitude A and the second amplitude range ends at the threshold amplitude A, the threshold amplitude A being determined by an adjustment signal; and wherein the amplification of the second input part also comprises an amplification with a linear gain, the linear gain of this amplification of the second input part being adjustable independently from the nonlinear gain or the linear gain of the amplification of the first input part. the splitting of the input signal into at least a first input part and a second input part; the amplification (3, 4) of at least the first input part with a linear gain to create a first output part and the amplification of at least the second input part of the input signal to create a second output part, wherein the amplification of the second input part comprises a nonlinear amplification; and summing the first output part and the second output part in order to provide an output signal, wherein the amplification characteristic of the output signal in relation to the input signal comprises a first amplitude range with an essentially linear first gain and a second amplitude range comprising a nonlinear gain covering lower amplitudes than the first amplitude range, whereby the nonlinear gain of the second amplitude range is always higher than or as high as the linear first gain of the first amplitude range; wherein an instant amplitude signal correlated to the second input part is generated and used for controlling the gain of the nonlinear amplification of the second input part, the instant amplitude signal being generated by producing a complex signal and then calculating the square root of the sum of the squares of the real and imaginary components of the complex signal, wherein the imaginary component of the complex signal represents a Hilbert transformation of the real component of the complex signal, and wherein the real and imaginary components of the complex signal both have the same amplitude spectrum as the second input part; wherein the first amplitude range begins at a threshold amplitude A and the second amplitude range ends at the threshold amplitude A, the threshold amplitude A being determined by an adjustment signal; and wherein the amplification of the second input part also comprises an amplification with a linear gain, the linear gain of this amplification of the second input part being adjustable independently from the nonlinear gain or the linear gain of the amplification of the first input part.