Patent ID: 6970569

Claim:
An audio processing apparatus for a headphone comprising: first filter means for processing n-channel audio signals in accordance with predetermined finite impulse response characteristics including a predetermined limited number of delay stages so as to preclude reflective sound components from being produced and for converting the n-channel (where n is a positive integer greater than or equal to 2) audio signals supplied from at least one signal source into a first channel signal and a second channel signal by mixing processed portions of the n-channel audio signals; a pair of second filter means, one second filter means having a first predetermined transfer function including reflective sound components and receiving the first channel signal and the other second filter means having a second predetermined transfer function different than said first predetermined transfer function and including reflective sound components and receiving the second channel signal output from the first filter means for providing an uncorrelated independent processing by setting different delay times corresponding to said first and second predetermined transfer functions to the first channel signal and the second channel signal, respectively, wherein the first channel signal remains separate from and unmixed with the second channel signal; and an output unit for respectively supplying signals output from the pair of second filter means to left and right loudspeaker units of the headphone, wherein the pair of second filter means each comprise a digital filter providing uncorrelated independent processing by setting delay times corresponding to the first and second predetermined transfer functions relating to reflective sound components using delay units having different delay times.