Patent ID: 7146013

Claim:
A microphone system that executes an adaptive signal processing by using output signals from two microphones and outputs a speaker's voice signal with an improved SN ratio, the microphone system comprising two microphones having directional characteristics, wherein the microphones are positioned relatively close to one another, both microphones are positioned in front of and above the position of the speaker's mouth by approximately the same distance, and the angles formed by the orientations of the microphones with respect to a speaker's vocalizing direction are different for each of the microphones, wherein the angle formed by the orientation of a first microphone with respect to the speaker's vocalizing direction is set to approximately 0°, and the angle formed by the orientation of a second microphone with respect to the speaker's vocalizing direction is set to approximately 45°; wherein a signal from the first microphone is supplied through a target response setter having a delay characteristic to a subtracter; a signal from the second microphone is supplied through an adaptive filter to the subtracter; and the output of the subtracter produces a difference signal that is supplied to the adaptive filter which executes adaptive signal processing on the basis of the LMS (Least Mean Square) algorithm so as to minimize the power of the difference signal.