Method for processing an acoustic input signal, preferably a speech signal, by an audio processing device, said method comprising the following steps: a) receiving a digital representation (S in ) of an acoustic input signal, b) calculating at least one statistical parameter (P) of the digital representation (S in ) of the acoustic input signal, c) calculating a compression ratio function (CR f ) based - on a prescribed constant compression ratio (CR pr ), said prescribed constant compression ratio (CR pr ) uniformly mapping acoustic input signals of a selected magnitude to acoustic output signals of a selected magnitude, and - on at least one statistical parameter (P) calculated in step b), wherein the compression ratio function (CRf) deviates from the prescribed constant compression ratio (CR pr ) by including a non-uniform mapping of acoustic input signals of a selected magnitude to acoustic output signals of a selected magnitude, wherein the nonuniformity of the mapping procedure is determined based on at least one statistical parameter (P) calculated according to step b), and d) applying the non-uniform compression ratio function (CRf) according to step c) on the digital representation (S in ) of the acoustic input signal delivering a digital representation (S out ) of an enhanced acoustic output signal, wherein the at least one statistical parameter (P) calculated in step b) comprises information with regard to the magnitudes of the input signal at given sample rates, characterized in that the at least one statistical parameter (P) calculated in step b) comprises a histogram of magnitudes of the input signal representing samples having a magnitude between 40 and 90 dB SPL and wherein the gradient of the non-uniform compression ratio function (CRf) essentially matches the envelope of the histogram. a) receiving a digital representation (S in ) of an acoustic input signal, b) calculating at least one statistical parameter (P) of the digital representation (S in ) of the acoustic input signal, c) calculating a compression ratio function (CR f ) based - on a prescribed constant compression ratio (CR pr ), said prescribed constant compression ratio (CR pr ) uniformly mapping acoustic input signals of a selected magnitude to acoustic output signals of a selected magnitude, and - on at least one statistical parameter (P) calculated in step b), wherein the compression ratio function (CRf) deviates from the prescribed constant compression ratio (CR pr ) by including a non-uniform mapping of acoustic input signals of a selected magnitude to acoustic output signals of a selected magnitude, wherein the nonuniformity of the mapping procedure is determined based on at least one statistical parameter (P) calculated according to step b), and - on a prescribed constant compression ratio (CR pr ), said prescribed constant compression ratio (CR pr ) uniformly mapping acoustic input signals of a selected magnitude to acoustic output signals of a selected magnitude, and - on at least one statistical parameter (P) calculated in step b), d) applying the non-uniform compression ratio function (CRf) according to step c) on the digital representation (S in ) of the acoustic input signal delivering a digital representation (S out ) of an enhanced acoustic output signal, wherein the at least one statistical parameter (P) calculated in step b) comprises information with regard to the magnitudes of the input signal at given sample rates, characterized in that the at least one statistical parameter (P) calculated in step b) comprises a histogram of magnitudes of the input signal representing samples having a magnitude between 40 and 90 dB SPL and wherein the gradient of the non-uniform compression ratio function (CRf) essentially matches the envelope of the histogram. <EOS>