Patent ID: 7672196
Filing Date: 2010-03-02
Classification: G01S

Abstract:
1. A sound source localizing apparatus, comprising: a receiving unit including first to fourth receivers each having a predetermined directivity and all disposed at a measuring point set in an arbitrary place to receive a signal coming from a sound source, the first receiver being pointed in a reference direction to show a highest directional sensitivity, second receiver being directed at an angle of 90 deg. to the reference direction to show a highest directional sensitivity, third receiver being directed at an angle of 180 deg. to the reference direction for a highest directional sensitivity, and the fourth receiver being directed at an angle of 270 deg. to the reference direction to show a highest directional sensitivity; a storage unit having stored therein a first sensitivity-difference data base including angle-by-angle differences in sensitivity between the first receiver directed in the reference direction to show the predetermined directivity and third receiver directed at the angle of 180 deg. to the reference direction to show the predetermined directivity and a second sensitivity-difference data base including angle-by-angle differences in sensitivity between the second receiver directed at the angle of 90 deg. to the reference direction to show the predetermined directivity and fourth receiver directed at the angle of 270 deg. to the reference direction to show the predetermined directivity; a time dividing unit to perform time division of the signals received by the first, second, third and fourth receivers, respectively, with an arbitrary time window width, a frequency analyzing unit to apply a Fourier transform to each of the signals subjected to the time division in the time dividing unit, a first calculating unit for calculating a difference in level in each arbitrary frequency band between a signal received by the first receiver and subjected to the Fourier transform in a frequency analyzing unit and the signal received by the third receiver and subjected to the Fourier transform in the frequency analyzing unit; a second calculating unit for calculating a difference in level in each arbitrary frequency band between a signal received by the second receiver and subjected to the Fourier transform in the frequency analyzing unit and the signal received by the fourth receiver and subjected to the Fourier transform in the frequency analyzing unit; an arrival-angle determining unit for making a comparison between a result of the calculation made in the first calculating unit and result of the calculation made in the second calculating unit to determine an arrival angle of the sound source on the basis of the result of comparison and with reference to a range used for determination of a sound-source arrival angle depending upon the first and second sensitivity-difference data bases stored in the storage unit; and an arrival-direction deciding unit for deciding an arrival direction of the sound source on the basis of the result of the determination made in the arrival-angle determining unit and with reference to a range used for determination of a sound-source arrival direction depending upon the first and second sensitivity-difference data bases stored in the storage unit, to thereby calculate a sound-source direction and sound level in each frequency band.