A Spatial Sound Localization System for Mobile Robots

In this paper, we described a robotic spatial sound localization system using four microphones arranged on the surface of a sphercial robot head. The four microphones, with three on the head center level and one on the top, provide spatial cues for sound elevation as well as azimuth. A weighted cross-correlation method based on the model of the precedence effect is used to calculate the time differences and suppress the influence of echoes. To integrate spatial cues of different microphone pairs, a mapping method from the correlation between different microphone pairs to a 2-D map corresponding to azimuth and elevation of sound sources was proposed. Experiments shows the system can provide the distribution of sound sources in azimuth-elevation space for sound sources, even concurrently in reverberant environments.