Capturing sound of target source located beyond noise source by line microphone array

Abstract

We had developed a method that captured the target sound when the noise source was located in front of the target source. It used a line microphone array whose direction was toward the noise source and created a spatial null sensitivity point at the noise source position. Our previous method, however, could reduce the noise only in a narrow area around the null point. To extend the noise reduction area, we developed a new method that creates some adjacent null points with more than two microphones. The experimental result showed that, if the target source was located 8 m distant from the microphone, the new method with three microphones could create a -20 dB noise reduction area whose center was 6 m distant from the microphone with a radius of 0.5 m, and captured the target sound without changing its timbre.