Patent ID: 7386139
Filing Date: 2008-06-10
Classification: H04R,H04S

Abstract:
1. A sound image control system for controlling sound image localization positions by reproducing an audio signal from a plurality of actual loudspeakers, said system comprising: at least four actual loudspeakers for reproducing the audio signal; and a signal processing section for setting four points corresponding to positions of both ears of first and second listeners as control points, and performing signal processing for the audio signal as input into each of said at least four actual loudspeakers so as to produce first and second target sound source positions, wherein the first and second target sound source positions, which are both virtual sound source positions and are produced individually for each of the first and second listeners, are sound image localization positions as perceived simultaneously and individually by the first and second listeners, respectively, such that the first target sound source position is in a direction relative to the first listener that extends from the first listener toward the second listener and is inclined at a predetermined azimuth angle, and the second target sound source position is in a direction relative to the second listener that extends from the first listener toward the second listener and is inclined at the predetermined azimuth angle, wherein said signal processing section has control characteristics which simultaneously give predetermined sound image control effect to the first and second listeners, and inputs control signals, a total number of the control signals being the same as a total number of the speakers, to the speakers to which the control signals respectively correspond, so as to reproduce sounds in a time-continuous manner, wherein said signal processing section is operable to control the first and second target sound source positions so that a distance from the second listener to the second target sound source position is shorter than a distance from the first listener to the first target sound source position, and wherein the control characteristics of said signal processing section are a solution of equations in each of which, at each of the four control points, combined characteristics obtained by combining the control signals of said processing section which have reached each of the four control points from said at least four actual loudspeakers to which the control signals respectively correspond are equal to transmission characteristics from each of the first and second target sound source positions to each of the four control points corresponding thereto.