Audio enhancement system

An audio enhancement system that compensates for linear distortions of a sound signal reproduced by an audio system in a listening room, the audio enhancement system comprising:

• a loudspeaker room listener system that receives an input signal and provides a loudspeaker room filtered signal;
• a reference transform that receives the input signal and provides a reference transform signal;
• an analysis filter bank having a plurality of analysis sub-filters, that receives the loudspeaker room filtered signal and generates a plurality of analysis output signals corresponding to different frequency ranges of the loudspeaker room filtered signal;
• a synthesis filter bank having a plurality of synthesis sub-filters, that generates an enhanced audio signal from a plurality of synthesis input signals, where the number of analysis output signals and the number of synthesis input signals are equal;
• and
• a processing unit connected between the analysis filter bank and the synthesis filter bank, the processing unit including a plurality of adaptive sub-band filters, where each adaptive sub-band filter receives one of the analysis output signals and generates a corresponding one of the synthesis input signals, where each adaptive sub-band filter forms an inverse filter for linearizing an unknown transfer function established by the audio system and the listening room in a respective frequency range;
• a summer that receives the reference transform signal and the enhanced audio signal, and provides an error signal indicative of the difference between the reference transform signal and the enhanced audio signal;
• and
• an adaption unit that receives the difference signal and the loudspeaker room filtered signal and generates filter coefficients for the plurality of adaptive sub-band filters;
• where the analysis filter bank and the synthesis filter bank each has a non-linear frequency resolution.