A talking robot and its autonomous learning of speech articulation for producing expressive speech

The author is developing a talking robot by reconstructing a human vocal system mechanically based on the physical model of human vocal organs. The robotic system consists of motor-controlled vocal organs such as vocal cords, a vocal tract and a nasal cavity to generate a natural voice imitating a human vocalization. By applying the technique of the mechanical construction and its adaptive control, the robot is able to autonomously reproduce a humanlike vocal articulation using its vocal organs. In vocalization, the vibration of vocal cords generates a source sound, and then the sound wave is led to a vocal tract, which works as a resonance filter to determine the spectrum envelope. For the autonomous acquisition of the robot's vocalization skills, an adaptive learning using an auditory feed-back control is introduced. In this manuscript, a human-like expressive speech production by the talking robot is presented. The construction of the talking robot and the autonomous acquisition of the vocal articulation are firstly introduced, and then the acquired control methods for producing human-like speech with various expressions will be described.