Microphone array sound source location system with imaging overlay
View Patent ↗In order to locate and display the source of a sound such as a noise at a factory or the like accurately even when it is outside, a pair of microphones (M 1 , M 3 ) and another pair of microphones (M 2 , M 4 ) are disposed on the X axis and Y axis with a distance L therebetween, respectively, the direction of the sound source is estimated from a difference between sound arrival times to the microphones (M 1 , M 3 ) and a difference between sound arrival times to the microphones (M 2 , M 4 ), an image around the estimated location of the sound source is picked up by a camera, and the above estimated location of the sound source is displayed on the above image displayed on the display of a personal computer.
1. A sound source locating system for determining a location of a sound source, comprising:
at least three microphones arranged two-dimensionally in two pairs, one of said two pairs being arranged on a first line, the other of said two pairs being arranged on a second line crossing the first line,
means of estimating the location of the sound source from a ratio of phase differences or arrival time differences of arrival sound between the two pairs of the microphones,
means of picking up an image around the location of the sound source, and
means of displaying the location of the sound source on the image.
2. The sound source locating system of claim 1 , further comprising a fourth microphone to form the two pairs of the microphones together with the at least three microphones, said two pairs of the microphones being arranged on the first line and the second line perpendicular to the first line to be spaced apart from each other by a predetermined distance, said means of estimating the location of the sound source measuring a difference between sound arrival times of each of the two pairs of the microphones so that the location of the sound source is estimated from the ratio of the arrival time differences.
3. A sound source locating system for determining a location of a sound source, comprising:
at least four microphones arranged threedimensionally, at least three microphones of said at least four microphones being arranged on a common plane in two pairs, at least one microphone of said at least four microphones being arranged away from the common plane, one of said two pairs being arranged on a first line, the other of said two pairs being arranged on a second line crossing the first line,
means of estimating the location of the sound source from a ratio of phase differences or arrival time differences of arrival sound between the two pairs of the microphones and phase differences or arrival time differences of arrival sound between the at least three microphones on the common plane and the at least one microphone away from the common plane,
means of picking up an image around the estimated location of the sound source, and
means of displaying the estimated location of the sound source on the picked up image.
4. The sound source locating system of claim 3 , further comprising one pair of microphones arranged on a third line crossing the first line and the second line to be spaced apart from each other by a predetermined distance, said means of estimating the location of the sound source measuring a difference between sound arrival times of each of the two pairs and the one pair of the microphones so that the location of the sound source is estimated from the ratio of the arrival time differences.
5. The sound source locating system of claim 3 which comprises microphones consisting of the two pairs of the microphones disposed on the first and second lines with a predetermined distance therebetween and a fifth microphone not existent on the common plane as the two pairs of the microphones, the means of estimating the location of the sound source from the phase differences among output signals of the microphones, the means of picking up the image around the estimated location of the sound source, and the means of displaying the estimated location of the sound source on the picked up image.
6. The sound source locating system of claim 5 , wherein the two pairs of the microphones are disposed on the first and second lines, respectively, to form a regular square, the fifth microphone is disposed on a straight line passing through the center of the regular square and perpendicular to the first and second lines, and the differences among the sound arrival times to the microphones are obtained to estimate the location of the sound source.
7. The sound source locating system of claim 6 , wherein the fifth microphone is arranged such that the distances between the fifth microphone and the other microphones forming the regular square are made equal to the distance between each pair of the microphones.
8. The sound source locating system of any one of claims 1 to 7 , wherein color of a symbol for the location of the sound source displayed is changed according to a level of sound pressure or a height of frequency.
9. The sound source locating system of claim 1 or 3 , wherein the microphones are moved to a plurality of positions.
10. The sound source locating system of claim 1 or 3 , wherein the microphones can be rotated.
11. The sound source locating system of claim 1 or 3 , wherein the microphones are used to collect sound at predetermined time intervals to estimate movement of the location of the sound source.
12. The sound source locating system of claim 1 or 3 which comprises means of measuring absolute locations of the microphones on ground.
13. The sound source locating system of claim 1 or 3 which comprises means of storing data on a sound pressure of the sound source which is collected by the microphones in a normal state and means of comparing newly collected sound pressure data with the stored sound pressure data.