Humanoid hearing: A novel three-dimensional approach

One of the key features of the human auditory system, is its nearly constant omni-directional sensitivity, e.g., the system reacts to alerting signals coming from a direction away from the sight of focused visual attention. In many surveillance situations where visual attention completely fails since the robot cameras have no direct line of sight with the sound sources, the ability to estimate the direction of the sources of danger relying on sound becomes extremely important. We present in this paper a novel method for sound localization of a static sound source in azimuth and elevation using a humanoid head equipped with two small microphones inserted into its artificial ear canals. We also tackle the moving sound source tracking problem. This new localization system demonstrated high precision in 3D and enabled a low-complexity implementation on the humanoid DSP platform.