Patent ID: 8526633

Claim:
An acoustic apparatus comprising: a plurality of microphone arrays arranged on a circumference around one axis and facing outwardly away the one axis along a plane that is orthogonal to the one axis; and a sound signal processing circuit that delays a phase of a sound signal output from each of the microphone arrays by an angle on the circumference at an installation position of each of the microphone arrays, wherein the sound signal processing circuit includes an adder that combines the sound signals delayed by the sound signal processing circuit, wherein an angle of one microphone array, among the microphone arrays, is set to 0 degrees as a reference angle, the one microphone array being arranged at a reference installation position, wherein the other microphone arrays, among the microphone arrays, are arranged at installation positions along the circumference so that the angles of the installation positions of the other microphone arrays from the reference position are increased along a circumferential direction around the one axis, respectively, and wherein the sound signal processing circuit delays the phase of the sound signal output from each of the other microphone arrays in accordance with the angle of each of the installation positions of the other microphone arrays from the reference installation position.