Patent ID: 7024008

Claim:
Apparatus for rapidly enhancing audio quality of an input audio signal in a portable computing system having limited resources and having a reproduction medium with unknown characteristics, comprising: a. a generator component for generating a predetermined finite set of M single frequency tones and for passing said set of tones to said reproduction medium to generate a subsequent output signal; b. a set of sub-band filters for receiving said subsequent output signal wherein each of the sub-band filters passes at least a frequency corresponding to one of the M tones; d. an estimating component for estimating the unknown characteristics of said reproduction medium by examining outputs of each of said sub-band filters after passing said subsequent output signal through said medium to produce gain estimates; and e. at least one filter construction component for dynamically constructing a set of sub-band inverse filters to compensate for the estimated characteristics of the reproduction medium, wherein, before passing an input audio signal through said reproduction medium, said audio signal are passed through said inverse filters, thereby improving the audio quality after the audio signal passes through said reproduction medium.