Based On Multiple Sound Sources Finding Method Microphone Array

Measuring multiple source direction in a microphone-array refers to that the direction of acousitc source is determined by mixed-signal imformation received from microphones. It is widely used in many areas, such as video/audio conferencing, speech recognition and speech enhancement etc. By estimating the speaker position to control the microphone and camera, then the automatic speech signal of the speaker can be enhanced.In the military area, the technology is widely used in the aspects of sniper detection and target detection of aircraft, artillery etc.Therefore, multiple sound source direction measurement is a new hotspot in acoustic signal processing field.This thesis mainly focuses on a study based on multiple sound source direction measurement technology. And the several categories of traditional sound source direction measurements are summarized and compared firstly. In this paper, the typical dual-microphone array is studied, focused on far-field multiple sound source mode, the degenerate unmixing estimation technique (DUET) based on W-Disjoint Orthogonality (W-DO) of the source signals is applied to the acousitc source direction measurement. The time delay estimation algorithm based on this characteristic has simple implementation, little computation.And it can measurement the directions of multiple acoustic sources with only two microphones.However, when the wavelength is less than twice the spacing of the two microphones, this kind of algorithm is prone to phase wrap-around aliasing, which often leads to artifacts. However the spacing can not be infinitely reduced, thus the practical applications is limited of such methods. In response to these problems, an approach to correct the phase wrap-around aliasing based on an iterative time-frequency masking process is presented in this paper. By iteratively clustering in the masked time-frequency plane and the artifacts due to the phase wrap-around aliasing can be extremely suppressed. In addition, combined with the speech endpoint detection technology that based on energy, the paper puts forward a real-time processing algorithm. For the above method, simulation and outdoor experiments are taken. The experimental results show that the method is superior to conventional DUET method, which proves that the method has a great practical application value.