Patent ID: 9445195
Filing Date: 2016-09-13
CPC Classification: G10L,H04R,H04S

Claim Text:
1. A directivity control method for controlling a directivity of a pair of microphones, the method comprising: a step of detecting a ratio of a pair of input signals input from the pair of microphones in accordance with a shifted amount in a direction of a sound source relative to a center of the pair of microphones; and a step of giving a directivity to emphasize or suppress the pair of input signals in accordance with the shifted amount of the sound source of the pair of input signals in the direction relative to the center of the pair of microphones by reflecting the ratio on the pair of input signals, wherein: in the detecting step, a coefficient m converging to the ratio is generated by causing both of the pair of input signals to be alternately approximated to each another, the detecting step comprises: a first step of alternately interchanging the pair of input signals for each one sample through an interchange circuit to generate a pair of interchanged signals; a second step of multiplying one of the interchanged signals by the coefficient m to generate an error signal between the one interchanged signal to which the coefficient m is multiplied and the other interchanged signal; and a third step of calculating a recurrence formula of the coefficient m containing the error signal to update the coefficient m for each one sample, and the directivity giving step comprises a fourth step of multiplying the pair of input signals by the sequentially updated coefficient m and outputting a result.