Spatial auditory processing for a hearing robot

We describe an auditory system for a multimodal mobile robot. The auditory system contains four microphones that are spatially arranged on a spherical robot head with three around the side of the sphere and one at the top. Different pairs of microphones provide localization cues for different directions. By using the top-mounted microphone, the elevation of sound sources can also be localized based on time difference and intensity difference cues. Different methods of spatial cue integration are proposed and compared. By incorporating a model of the precedence effect, the influence of echoes and reverberations can be inhibited.