Patent ID: 7539319
Filing Date: 2009-05-26
Classification: H04S

Abstract:
1. An apparatus including a programmable processor or a semi-custom or full-custom dedicated processor, or one or more programmable logic devices, the apparatus comprising: (a) a first mixer configured to accept a set of audio inputs and a set of feedback inputs and to form a first predetermined combination of said audio inputs and of said feedback inputs as intermediate output signals, the audio inputs representing audio signals, each audio signal being projected from an idealized sound source located at a respective spatial sound source location relative to a listener location, the set of audio inputs including at least a left audio input and a right audio input; (b) a filter system configured to filter said intermediate output signals to form filtered intermediate output signals and to filter a second predetermined combination of a plurality of said input signals to produce said feedback inputs, the filter system including one or more filters applied to said intermediate output signal to account for the direct response of a room and one or more filters applied to the second predetermined combination to account for a non-directional approximation to the reverberant response of the room, the filter system including feedback response filtering of said second predetermined combination, such that the filtered intermediate output signals include filtered direct response signals, and filtered reverberant signals that also account for the direct response, wherein said feedback inputs are non-directional; and (c) a second mixer configured to accept said filtered intermediate output signals and to determine left and right channel stereo outputs for oppositely opposed headphones, the determining being by mixing of said filtered intermediate output signals, such that a listener at the listener location and listening using the oppositely opposed headphones has the sensation of a sound source being spatially distant from the area between said pair of headphones.