Patent ID: 7636443

Claim:
An apparatus for enhancing sound, the apparatus comprising: a first input and a second input of original audio data, wherein the audio data comprises a full range of frequencies within an original audio band without passing through a subsonic filter; a difference circuit configured to identify difference information in the first and second inputs, wherein the difference information has bass components filtered therefrom; an equalizer configured to spectrally shape the difference information, wherein the difference information is spectrally shaped by the equalizer by applying a perspective curve characterized by a maximum gain within a first frequency range of 100 to 150 Hz and the curve characterized by a minimum gain within a second frequency range of 1680 to 2520 Hz, wherein the curve decreases at a rate of approximately 6 decibels per octave below the first frequency range and above the first frequency range towards the second frequency range, the curve further increasing at a rate of approximately 6 decibels per octave above the second frequency range; a summing circuit configured to combine the spectrally shaped difference information with at least a portion of the original audio data in the first input to generate a first output comprising the spectrally shaped difference information and the original audio data in the first input including at least a portion of the bass components that were filtered from the spectrally shaped difference information, and the summing circuit further configured to combine the spectrally shaped difference information with at least a portion of the original audio data in the second input to generate a second output comprising the spectrally shaped difference information and the original data in the second input including at least a portion of the bass components filtered from the spectrally shaped difference information.