Microphone array sound source location system with imaging overlay

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 (M1, M3) and another pair of microphones (M2, M4) 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 (M1, M3) and a difference between sound arrival times to the microphones (M2, M4), 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.