Real time robot audition system incorporating both 3D sound source localisation and voice characterisation

This paper describes the implementation of a novel real time robot audition system which combines a 3D sound localisation system and a voice characterisation (VC) system. The localisation system employs a 4 microphone array and uses the time delay estimation method. Accuracy is improved through the use of a correlation confidence threshold and a median filter. The VC system, which classifies between speech, non speech and silence, uses a decision tree classifier and a feature set comprising MFCCs, mean MFCCs and variance in MFCCs. The complete system has a processing time of 0.73x real time, and a range of up to 3 m. The compact design, high accuracy, and real time processing ability makes the system and the approach well suited to robotics.