Patent ID: 8335321

Claim:
An audio signal processing method comprising the steps of: generating audio signals having an omni-directivity in the whole circumferential direction by first, second and third omni-directional microphones each of which receives sound; adding audio signals generated by the first, second third omni-directional microphones and generating an audio signal having an omni-directivity in the whole circumferential direction; subtracting audio signals generated by the first and third omni-directional microphones and generating an audio signal having a directivity in the right-left direction; adding audio signals generated by the first and third omni-directional microphones; subtracting an audio signal generated by the second omni-directional microphone from the added audio signal generated by the first and third omni-directional microphones and generating an audio signal having a directivity in the front-back direction; and adding the audio signal resulting from the multiplication of the audio signal having a directivity in the whole circumferential direction by a predetermined coefficient, the audio signal resulting from the multiplication of the audio signal having a directivity in the right-left direction by a predetermined coefficient, and the audio signal resulting from the multiplication of the audio signal having a directivity in the front-back direction by a predetermined coefficient and generating a unidirectional audio signal.